Transferring an antenna to an rfid inlay substrate

ABSTRACT

Forming antenna structures having several conductor turns (wire, foil, conductive material) on a an antenna substrate (carrier layer or film or web), removing the antenna structures individually from the antenna substrate using pick &amp; place gantry or by means of die punching, laser cutting or laminating, and transferring the antenna structure with it&#39;s end portions (termination ends) in a fixed position for mounting onto or into selected transponder sites on an inlay substrate, and connecting the aligned termination ends of the antenna structure to an RFID (radio frequency identification) chip or chip module disposed on or in the inlay substrate. A contact transfer process is capable of transferring several antenna structures simultaneously to several transponder sites.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This is a continuation of U.S. Ser. No. 13/027,415 filed Feb. 15, 2011.

U.S. Ser. No. 13/027,415 is a continuation-in-part of U.S. Ser. No.12/877,085 filed Sep. 7, 2010, which is

-   -   a nonprovisional of U.S. 61/259,224 filed Nov. 9, 2009    -   a nonprovisional of U.S. 61/351,902 filed Jun. 6, 2010    -   a nonprovisional of U.S. 61/361,895 filed Jul. 6, 2010    -   a nonprovisional of U.S. 61/367,466 filed Jul. 26, 2010

U.S. Ser. No. 13/027,415 is a continuation-in-part of U.S. Ser. No.12/901,590 filed Oct. 11, 2010

U.S. Ser. No. 13/027,415 is a nonprovisional of U.S. 61/331,368 filedMay 4, 2010

U.S. Ser. No. 13/027,415 is a nonprovisional of U.S. 61/363,763 filedJul. 13, 2010

U.S. Ser. No. 13/027,415 is a nonprovisional of U.S. 61/414,408 filedNov. 16, 2010

U.S. Ser. No. 13/027,415 is a nonprovisional of U.S. 61/437,795 filedJan. 31, 2011

U.S. Ser. No. 13/027,415 is a nonprovisional of U.S. 61/437,649 filedJan. 30, 2011

U.S. Ser. No. 13/027,415 is a nonprovisional of U.S. 61/442,284 filedFeb. 13, 2011

TECHNICAL FIELD

The invention relates to “inlay substrates” used in the production of“inlays” for “security documents” such as electronic passports,electronic ID cards and smart cards and, more particularly, for example,to how an antenna may be mounted to the inlay substrate (and connectedto an RFID (radio frequency identification) chip or chip module disposedon the inlay substrate).

BACKGROUND

Transponders are electronic devices incorporated into secure documentssuch as “smart cards” and “electronic passports” using RFID (radiofrequency identification) technology.

The transponder (or inlay, or chip card) itself generally comprises(includes):

-   -   a substrate (or inlay substrate) which may comprise a sheet of a        synthetic material or paper;    -   a chip (or chip module, chip unit or naked die) installed on the        substrate (or in a recess in the surface of the substrate) and        having terminals (or contact surfaces, or pads); and    -   an antenna wire (or conductor) mounted on or in the substrate,        formed with “turns” as a flat (substantially planar) coil and        connected (bonded) by its ends or end portions to the terminals        (terminal areas) of the chip module.

The inlay substrate may comprise one or more layers of PolyvinylChloride (PVC), Polycarbonate (PC), polyethylene (PE), PET (doped PE),PETE (derivative of PE), TYVEK, Teslin™, Paper or Cotton/Noil, and thelike. For example, a single layer of uncoated Teslin™, with a thicknessof 356 microns. In the main hereinafter, inlay substrates comprisingTeslin™ or polycarbonate (PC) will be described.

Teslin™ is a synthetic printing media, manufactured by PPG Industries.Teslin™ is a waterproof synthetic material that works well with anInkjet printer, Laser printer, or Thermal printer. Teslin™ is alsosingle-layer, uncoated film, and extremely strong. In fact, the strengthof the lamination peel of a Teslin™ sheet is 2-4 times stronger thanother coated synthetic and coated papers. Teslin™ comes in the sizes of7 mil to 18 mil, though only sizes 10 mil and 14 mil are sized at 8.5″by 11″, for printing with most consumer printers. Also available areperforated versions of Teslin, specifically, 2up, 6up, and 8up. Teslin™is a microporous polymer. Polycarbonate (PC) is typically used fornational ID cards, and also as the material in certain passports (suchas for the Datapage, in contrast to the e-Cover).

The inlay substrate may have an area designated as a “transponder site”whereat the chip module and antenna will be installed. (A recess in theinlay substrate may constitute the transponder site.) The transpondersite may itself have two areas designated as “terminals areas”corresponding in position to the two terminals of the chip module whichwill be installed at the transponder site. (The transponder site andterminal areas are generally geometric abstractions, the chip module andterminals are physical elements.) Hence, it should be understood that,where applicable, the terms (and reference numerals for) “transpondersite” and “chip module” may be used interchangeably, and that the terms“terminal areas” and “terminals” may similarly be used interchangeably.

In the main hereinafter, RFID chips incorporated into chip modules willbe described. The chip module may be a leadframe-type chip modulecomprising an RFID chip encapsulated by a mold mass and supported by andconnected to a leadframe having two terminal areas.

-   -   the mold mass may be approximately 240 μm thick and 5 mm wide    -   the leadframe may be approximately 80 μm thick and 8 mm wide.

The chip module may be disposed in a recess extending into the surfaceof the substrate measuring for example 5.5 mm wide×8.5 mm high(generally the recess is only slightly larger than the chip module toallow some clearance during installation, while maintaining goodregistration).

The recess for receiving the chip module extends into the inlaysubstrate from a “top” surface thereof, and may be a “window” typerecess extending completely through the inlay substrate to a “bottom”surface thereof, or the recess may be a “pocket” type recess extendingonly partially through the inlay substrate towards the bottom surfacethereof.

The recess may have a “straight” profile—in other words, substantiallyconstant cross-dimension through (or into) the inlay substrate. Or, therecess may have a “stepped” profile, including a larger cross-dimensionat the top surface of the substrate than at (or towards) the bottomsurface of the inlay substrate. The recess is generally sized and shapedto accommodate the size and shape of the chip module being disposedtherein. The term “cavity” may be used interchangeably with “recess”. Astepped recess profile is commonly used to accommodate a leadframemodule, since the leadframe is typically wider (8-10 mm) than the moldmass (4-6 mm) of the chip module.

The antenna wire can be self-bonding copper wire or partially coatedself-bonding copper wire, enamel copper wire or partially coated enamelwire, silver coated copper wire, un-insulated wire, aluminum wire, dopedcopper wire or Litz wire.

The conventional method of mounting the wire is using a sonotrode toolwhich vibrates, feeds the wire out of a capillary, and embeds it intothe surface of the substrate. Examples of embedding a wire in asubstrate, in the form of a flat coil, and an ultrasonic tool forperforming the embedding (and a discussion of bonding), may be found inU.S. Pat. No. 6,698,089 (refer, for example, to FIGS. 1, 2, 4, 5, 12 and13 of the patent). See also FIGS. 1 and 2 of U.S. Pat. No. 6,233,818.Both of these patents are incorporated by reference herein. It is alsoknown that a coated, self-bonding wire will stick to a synthetic (e.g.,plastic) substrate because when vibrated sufficiently to soften (makesticky) the coating and the substrate.

The conventional method for connecting the ends or end portions of theantenna wire to the terminals (or “terminal areas”) of the chip moduleis by means of thermo compression (TC) bonding. This method makes use ofheat by passing pulses of electric current through a thermode andsimultaneously applying pressure to cause a diffusion process betweenthe wire and the leadframe of the chip module.

FIGS. 1A and 1B illustrate an example of a prior art technique, such asis disclosed in U.S. Pat. No. 6,233,818 for mounting an antenna wire toan inlay substrate and connecting the antenna wire to a chip moduleinstalled in a recess in the inlay substrate.

An inlay sheet 100 is a large inlay substrate which may have a pluralityof transponder areas (or sites), a one of which is shown in some detail.Typically, several transponders (or transponder sites) are fabricated ona single inlay sheet.

A recess 106 is formed in the inlay substrate 102 for receiving aleadframe type RFID chip module 108, positioned as shown, with the moldmass 112 situated below a leadframe 114. The recess 106 is illustratedas a pocket-type recess extending only partially through the inlaysubstrate 102, which is shown as a single layer substrate. The inlaysubstrate may comprise multi-layers, such as two layers as indicated bythe dashed lines passing across the substrate. Compare FIG. 1F.

The leadframe 114 of the chip module 108 has two terminal areas 108 aand 108 b. An antenna wire 110 having two connection portions (ends orend portions) 110 a and 110 b is mounted on or to the inlay substrate102 and connected to the terminal areas 108 a and 108 b of the chipmodule 108.

The antenna wire 110 may be mounted to the substrate using an ultrasonicembedding tool such as a sonotrode having a capillary 116. Mounting theantenna wire 110 may proceed as follows:

-   -   using the sonotrode, embed the wire a short distance, between        the points “a” and “b” near a first terminal of the chip module.        (embedding is indicated by the symbols “x”)    -   stop embedding (raise the sonotrode), and pass over the first        terminal 108 a of the chip module 108, between the points “b”        and “c”.    -   lower the sonotrode and resume embedding at the point “c”, and        form the turns of the antenna between the points “c” and “d”        (embedding is indicated by the symbols “x”)        -   there may be for example 4 or 5 turns, and the overall            length of the antenna wire may be 104 cm        -   notice that in forming the turns of the antenna, the wire            may need to cross over itself, thus requiring an insulated            wire. However, in some cases, the antenna wire does not need            to cross over itself. See, for example, FIG. 4 of U.S. Pat.            No. 6,698,089.    -   after approaching near the second terminal 108 b of the chip        module 108, stop embedding and pass over the second terminal of        the chip module, between the points “d” and “e”.    -   resume embedding a short distance on the opposite side of the        chip module, between the points “e” and “f”.

The embedding process (between the points “c” and “d”) may bediscontinuous, at several points, rather than continuous.

In a next stage of the process, the “connection” portions of the wirepassing over the terminal areas 108 a and 108 b are interconnected tothe terminal areas of the chip module, typically by means of thermocompression bonding. (A first connection portion between the points “b”and “c” passes over the terminal 108 a. A second connection portionbetween the points “d” and “e” passes over the terminal 108 b.) Athermode 118 for performing bonding of the connection portions to thecorresponding terminals is illustrated. It is known to remove insulationfrom the connection portions of the antenna wire to improve bonding.

In the case of an inlay substrate comprising Teslin™ (a syntheticpaper), a normal insulated wire would not properly embed into thematerial, it would detach. Therefore, it is known to use self-bondingwire which attaches to the material with a slight penetration of thewire in the material.

A self-bonding (or self-adhering) wire may comprise

-   -   a metallic core (typically, but not necessarily round in        cross-section) comprising copper, aluminum, doped copper, gold,        or Litz wire, and may have a diameter of 0.010-0.50 mm    -   a first coating or “base coat” comprising modified polyurethane,        and having a thickness of only a few microns    -   a second coating comprising polyvinylbutyral or polyamide, and        having a thickness of only a few microns.

The transponder thus formed on the inlay substrate may be incorporated,for example, in an electronic passport cover, as described hereinbelow.

Some Examples of Chip Modules

In the main hereinafter, the discussion may focus on RFID chip moduleswhich are leadframe-type modules. However, some of the techniques forproducing security documents discussed herein may also be applicable toepoxy glass modules (chip on FR4, wire bonded, glob topped).

FIG. 1C shows an example of an RFID chip module which is a “leadframemodule” comprising:

-   -   a leadframe having a thickness of approximately 80 μm    -   an RFID chip disposed on and connected by wire bonds to the        leadframe, having a thickness of approximately 80 μm    -   a mold mass disposed over the chip and wire bonds, having a        thickness of approximately 240 μm    -   an antenna wire having end portions connected to “connection        areas” of the leadframe, typically on a side of the leadframe        opposite the RFID chip (as shown), but the end portions can also        be connected to connection areas on the same side of the lead        frame as the RFID chip.

The total thickness of the leadframe module may be 320 μm, such as foran inlay substrate having a thickness of approximately 356 μm.Generally, the chip module will be disposed in a recess in the inlaysubstrate so as to be concealed therein.

FIG. 1D shows an example of an RFID chip module which is an “epoxy glassmodule” comprising:

-   -   an interconnect substrate, such as FR4 (printed circuit board        substrate material), having a thickness of approximately 100 μm        (FR4 is 100 μm and the chip & glob top 160 μm=overall 260 μm)    -   an RFID chip, wire-bonded (alternatively flip-chip connected        with solder bumps and underfiller, as illustrated) to the FR4        substrate, having a thickness of approximately 100 μm    -   a glob top epoxy disposed over the chip and connections, having        a thickness with chip of approximately 160 μm    -   an antenna wire having ends connected to “connection pads”,        typically on the same side of the FR4 substrate as the RFID        chip, but can also be connected on the opposite side of the FR4        substrate as the chip.

The total thickness of the epoxy glass module may be 260 μm, such as foran inlay substrate having a thickness of approximately 365 μm.Generally, the chip module will be disposed in a recess in the inlaysubstrate so as to be concealed therein.

Generally speaking, epoxy glass modules are inherently somewhat moreflexible than leadframe modules. This is a factor that may need to betaken into consideration when incorporating an RFID module into a securedocument. And, whereas leadframe modules are typically rectangular, themold part (glob top) of an epoxy glass module are typically round.

It should be understood that, although FIG. 1D shows a flip chipconnection between the RFID chip and the FR4 substrate, the chip can bewire-bonded to the substrate (such as shown in FIG. 1C, for theleadframe-type module.)

Portions of the Antenna Wire

FIG. 1E shows a flat coil antenna structure having several (such as fouror five turns) which may be formed of wire, such as self-bonding wire,and various portions of the resulting antenna structure, such as:

-   -   two ends which are generally the geometric “ends” of the        elongate antenna wire    -   two end segments which are generally short portions of the        antenna wire at each end of the antenna wire. The end segments        include the ends, and may be connected to the terminals of the        chip module, such as in U.S. Pat. No. 6,088,230 or US        2010/0141453.    -   two end portions which are also short portions of the antenna        wire (exclusive of the ends or end segments) which may be        connected to the terminals of the chip module, such as in U.S.        Pat. No. 6,233,818 or U.S. Pat. No. 7,546,671.    -   a main or intermediate portion which is the longest portion of        the antenna wire, between the two end portions, and which may be        formed into several turns of a flat coil antenna (the        intermediate portion may be referred to as the “main body        portion” of the antenna wire)

The “connection portions” of the antenna wire may be the ends (typicallyincluding end segments) or end portions (typically excluding endsegments). In some embodiments, reference is made to “termination ends”of the antenna, which may mean substantially the same thing as“connection portions”.

Some Examples of “Final Products”

Transponders such as are shown in FIGS. 1A and 1B may be considered tobe “interim products” in that some further steps or elements may beneeded before getting the product into the “hands of the consumer”. Forexample, various cover layers may be laminated to the inlay substrate toprotect (and secure) the transponder, as well as for imprinting withinformation. The end result, or “final product”, may be a securedocument such as an electronic passport booklet or a smart card.

FIG. 1F shows an example of a security document which may be a NationalID (identification) Card (or electronic ID, “eID” card) comprising amulti-layer (2 layer) inlay substrate, and additional layers comprisinga top overlay layer and a bottom overlay layer. An RFID chip module andcorresponding antenna (not shown) may be mounted in the inlaysubstrate(s). The chip module (not shown) may have a mold mass and aleadframe. The additional top and bottom layers may be anti-scratchlayers, and protect the inlay substrate(s). The eID card, inlaysubstrate layer and top and bottom layers are not shown to scale.

Some dimensions for and properties of the layers may be:

Top overlay layer transparent 80 microns Inlay substrate mold white 185microns  Inlay Substrate - Lead transparent 80 microns Bottom OverlayLayer transparent 80 microns

The layers of the inlay substrate for a smart card may comprise PVC,which has limited life. Smart cards are often replaced (renewed) everyfew years.

The layers of the inlay substrate for a national ID care may comprise PC(polycarbonate), which may be more durable (longer life) than PVC(polyvinyl chloride).

FIGS. 1G, 1H, 1I illustrate an exemplary construction for an electronicpassport cover, corresponding generally to the single layer inlaysubstrate construction shown in FIG. 1B. The inlay substrate for a USpassport may comprise Teslin™.

A cover layer may be disposed over the inlay substrate for the finalproduct. The material for the cover layer may be a cloth product, withchemistry in the coatings and a leather-like appearance to the cloth,such as by Holliston Inc. (905 Holliston Mills Road, Church Hill, Tenn.37642; www.holliston.com)

The cover layer may be laminated (joined) to the inlay substrate using apolyurethane hot melt adhesive, such as approximately 50-80 μm thick.Prior to the adhesive process, the inlay substrate may be pre-pressed toensure that the antenna wire does not protrude over (extend above) thesurface of the Teslin™ substrate, in other words, to ensure that theantenna wire is fully embedded in the inlay substrate.

With reference to FIG. 1H, in variations of the construction shown foran electronic passport cover (a similar secure document), the inlaysubstrate may be multi-layer, and if the recess extends completelythrough the inlay substrate, an underlying bottom layer may be providedto support the chip module.

Some dimensions for and properties of the layers of a passport cover maybe:

cover layer cloth 350 microns Inlay substrate Teslin ™ 356 microns

Mounting the Antenna to the Inlay Substrate

Various methods are known for mounting an antenna wire to the inlaysubstrate, and can generally be divided into two categories:

-   -   (i) “coil winding”, which comprises forming the antenna wire        separately from the inlay substrate and installing the preformed        antenna wire (sometimes with the chip module already mounted to        ends of the antenna wire) thereto, and    -   (ii) “common substrate”, which comprises forming the antenna        wire on the inlay substrate by scribing (typically ultrasonic        embedding), and connecting ends or end portions of the antenna        wire to terminal areas of the chip module

Some of these techniques are described in the following patents and/orpublications, all of which are incorporated by reference in theirentirety herein.

U.S. Pat. No. 5,809,633 (Mundigl et al.), incorporated in its entiretyby reference herein, discloses a method for producing a smart cardmodule for contactless smart cards. As disclosed therein:

-   -   A method for producing a smart card module includes bonding one        end of a thin wire onto a first contact zone of a semiconductor        chip. The wire is guided in a plurality of turns forming an        antenna coil. The wire is bonded onto a second contact area of        the semiconductor chip. The wire turns of the antenna coil and        the semiconductor chip are placed on a carrier body. (Abstract)    -   Referring now in detail to the single FIGURE of the drawing,        there is seen a flat carrier body 1 which is made of flexible,        non-conductive material and has a recess 2. A semiconductor chip        3 is inserted into the recess. The semiconductor chip 3 has two        contact zones 4 which are enlarged in comparison with the        customary chip contact zones through the use of a gold plating,        for example. Connections 6 of an antenna coil 5 are secured on        the contact zones 4 through the use of bond contacts. The        antenna coil 5 is a wire which is advantageously made of        aluminum. In this case, the wire has initially been bonded onto        one of the contact zones 4, then wound through the use of a        guiding head of an automatic wire-winding machine, into which a        bonding device is integrated, in a plurality of turns to form        the coil (only two turns are illustrated in the FIGURE, but        there may also be more) and finally bonded again onto the other        contact zone. The semiconductor chip 3 with the coil 5 which is        secured thereto in an inventive manner is subsequently inserted        into the recess 2 in the carrier body 1, with the result that        the coil 5 is disposed on the carrier body 1. (column 2, lines        35-54)

A known method of transferring a wire antenna onto or into a substrateis first to wind a coil on a mechanical fixture which includes amechanism to hold an RFID chip in position, and through rotation of thetool a coil is formed with its wire ends positioned over the terminalareas of the chip (or chip module) for interconnection. For example, SeeEP 0 839 360, incorporated by reference herein. The antenna wire can beself-bonding wire which, when heated during the rotation of the coilwinding tool, would form an antenna in which the turns of wire may beadhesively attached to one another.

U.S. Pat. No. 6,295,720 (Finn et al.), incorporated in its entirety byreference herein, describes a procedure of forming an antenna in aradial coil winding tool and mounting a chip in the tool before windingso as to arrange the wire ends of the coil over the terminal areas ofthe chip and then connecting the wire ends of the coil to the chipbefore placing the transponder (coil and connected chip) onto asubstrate. See also EP 0 922 289, WO98/09305, PCT/DE97/017712).

EP 0 839 360 (Finn et al.), Verfahren and Vorrichtung zur Herstellungeines IC-Kartenmoduls, incorporated in its entirety by reference herein,discloses another coil winding technique. See also WO97/04415(PCT/DE96/01121).

EP 1 352 551 (Michalk), incorporated in its entirety by referenceherein, describes a procedure for fitting conductor wires on or in asubstrate, with a conductor wire arrangement created outside thesubstrate before subsequently pressing the wire arrangement into saidsubstrate, by first applying a pattern of conductor wire on a tensioningframe with the conductor wire being tightened in parallel or almost inparallel to the pressing plane of the tensioning frame via tensioningelements having a predefined pattern, and the conductor wire patternbeing subsequently pressed and fixed in or on the substratecharacterized in that during the pressing of the conductor wire patterninto the substrate, the tensioning elements slide back according to thepressing movement and release the conductor wire pattern, and in thatthe axially movable tensioning elements are pushed forward one after theother according to the conductor wire arrangement to be created from thepressing plane one after the other starting from the inside part of theconductor wire arrangement, thus creating the conductor wire patternarrangement by a winding process.

To interconnect the wire ends of the wound coil to an RFID chip, theabove procedure proposes that the electronic component be contacted onthe tensioning frame with the conductor wire ends, and be pressed intothe substrate together with the coil.

The procedure of forming a wire antenna or transponder unit using a coilwinding process and then pressing the coil into a substrate by means ofheat and pressure is highly unreliable, slow and difficult to automatefor volume production. The tooling is also subject to wear and tearresulting in coils having different geometrical dimensions. One majordisadvantage of this technique is the inability to form an antenna witha large pitch between the wire conductors which form the antenna.

U.S. Pat. No. 6,088,230, incorporated in its entirety by referenceherein, overcomes some of the technical issues associated in using thetechnique of coil winding to produce a transponder site on a substrate.It describes a method of arranging a transponder site comprising atleast one chip and one wire coil on a substrate, in particular asubstrate used to produce a chip card, in which the chip and the wirecoil are disposed on a common substrate and the coil wire ends arebonded to terminal areas of the chip on the substrate characterized inthat the coil is formed by laying a coil wire in a wiring plane on thesubstrate, with the coil wire being bonded to the substrate at least atsome points. See also EP 0 753 180

This technique of laying a wire onto or into a substrate and forming anantenna for connection to an RFID chip in producing a transponder siteis known as “wire embedding”, and comprises using ultrasonic energy(delivered by a sonotrode) to stick the wire to or countersink the wirepartially or entirely into a synthetic substrate (the inlay substrate).

Furtherer examples of the common substrate technique can be found inU.S. Pat. No. 6,233,818 (Finn et al.) and subsequent U.S. Pat. No.6,698,089 (Finn et al.), both of which are, incorporated in its entiretyby reference herein. Generally, as disclosed therein,

Process and device for the contacting of a wire conductor (113) in thecourse of the manufacture of a transponder unit arranged on a substrate(111) and comprising a wire coil (112) and a chip unit (115), wherein ina first phase the wire conductor (113) is guided away via the terminalarea (118, 119) or a region accepting the terminal area and is fixed onthe substrate (111) relative to the terminal area (118, 119) or theregion assigned to the terminal area, and in a second phase theconnection of the wire conductor (113) to the terminal area (118,119) iseffected by means of a connecting instrument (125). (Abstract, '818)

U.S. Pat. No. 6,233,818 discloses a conventional technique for mountingand connecting an antenna wire. FIGS. 4 and 5 of this patent show that afirst end of the antenna wire starts on the substrate, passes over afirst chip terminal, then continues on the substrate to form the (4 or5) turns of the antenna, then passes over the second chip terminal, thenterminates on the substrate.

U.S. Pat. No. 6,088,230 discloses a procedure for producing atransponder unit (55) provided with at least one chip (16) and one coil(18), and in particular a chip card/chip-mounting board (17) wherein thechip and the coil are mounted on one common substrate (15) and the coilis formed by installing a coil wire (21) and connecting the coil-wireends (19, 23) to the contact surfaces (20, 24) of the chip on thesubstrate.

A wire embedding technique may be found in U.S. Pat. No. 6,626,364(Taban), incorporated in its entirety by reference herein.

Although these common substrate techniques represent a significantimprovement over coil winding in terms of antenna quality andthroughput, they have the disadvantage that different inlay formats(such as the pattern of the antenna coil) require significant mechanicalalterations to the production equipment resulting in downtime andinefficient use of the equipment, in particular where the number oftransponder sites on a format is very low, as is the case in theproduction of inlays for electronic passports (“2up” or “3up” formats).

U.S. Pat. No. 7,229,022 (Rietzler), incorporated in its entirety byreference herein, discloses method for producing a contactless chip cardand chip card produced according to said method. As disclosed therein:

The invention relates to a method for producing a transponder,especially a contactless chip card (1) comprising at least oneelectronic component (chip module 2) and at least one antenna (3); theat least one electronic chip component (2) being disposed on anon-conducting substrate that serves as a support for the component. Theat least one antenna is also disposed on a non-conducting substrate, theat least one electronic component (2) being applied to a first substrateand the antenna (3) on a second substrate. The entire circuit (1) isthen produced by joining the individual substrates so that they arecorrectly positioned relative to each other. The components (2, 3) arecontacted once the different substrates have been joint by means ofauxiliary materials such as solder or glue, or without auxiliarymaterials by microwelding. The non-conducting substrates form a basecard body. (Abstract)

FIG. 3 shows the individual substrate before the assembly in the usearrangement. Substrate 11 supports the antenna 12, whereby this isarranged exactly in the defined use arrangement and position. On theantenna substrate, assistance lines 13 can be applied, which simplifythe orientation on one another of both substrates. The antennae 12 lieon the underside of the substrates, that is, on the side facing towardthe second substrate. The second substrate 14 shows the substrate onwhich the chip modules 15 already are mounted. The chip modules arealready fixed onto the substrate by means of the previously describedmethod. The chip modules 15 lie on the top side, that is, on the side ofthe substrate facing the antennae 12.

For further processing, both substrates 11 and 14 are oriented to becorrectly position and pressed onto one another.

FIG. 4 shows the view of the joined substrates of a transponder in crosssection. One recognizes the lower substrate 16 on which the chip module17 is arranged. Opposite is the upper substrate 20, which supports theantenna 19 on its underside. In the contact region 18, the antenna 19and the contact surfaces 23 of the chip module overlap. At this point,the electrical connection is formed.

In this view, additionally an equalizing substrate 21 is shown. Thissubstrate does not support any components, rather contains only anopening 22, in which the chip module 17 comes to rest after the assemblyprocess. (column 5, lines 11-37)

US 2008/0314990 (Rietzler), incorporated in its entirety by referenceherein, discloses chip card and method for the production of a chipcard. See also WO07/065,404. As disclosed therein,

The invention pertains to a chip card and to a method for producing achip card with a chip module that is contacted with an external contactarrangement arranged in the contact surface of a card body, as well aswith an antenna device arranged in a card inlay, wherein the card inlayis initially produced in a first production device and the card inlay issubsequently provided with at least one respective external layer onboth sides in a second production device, namely in such a way that theexternal contact arrangement arranged on the external contact side ofthe chip carrier is introduced into a recess of the assigned externallayer, and wherein a connection between the card inlay and the externallayers is subsequently produced in a laminating process. (Abstract)

FIG. 1 shows an arrangement of a plurality of so-called panel sheetsthat respectively feature a plurality of layers interconnected in onepiece in the form of a panel arrangement in order to produce a cardinlay sheet 10 according to FIG. 5 with a plurality of interconnectedcard inlays 11. FIG. 1 specifically shows a receptacle layer sheet 12with a plurality of interconnected receptacle layers 13 and a coverlayer sheet 14 with a plurality of interconnected cover layers 15.

The receptacle layer sheet 12 and the cover layer sheet 14 are situatedbetween a lower laminator plate 17 and an upper laminator plate 18 of alaminator arrangement 16. The lower laminator plate 17 is provided withan arrangement 19 of recesses 20 corresponding to the panel arrangementof the receptacle layer sheet 12 and serving for accommodating acorresponding number of chip modules 21.

The receptacle layers 13 of the receptacle layer sheet 12 respectivelyserve as antenna substrates, on which one respective antenna device 22with several antenna windings 23 is arranged, namely in the form of awire arrangement in the example shown. The antenna devices 22respectively feature two contact ends 24, 25 that extend over contactingbays 26 in an opening edge 27 of a recess 28.

The receptacle layer sheet 12, as well as the cover layer sheet 14,consists of a plastic material that can be laminated such as, forexample, polyethylene or PVC.

The Rietzler references (U.S. Pat. No. 7,229,022 and US 2008/0314990)may be considered to be a “modified” form of coil winding in thatantenna structures are formed on a substrate other than the inlay (chipmodule containing) substrate.

In the teachings of U.S. Pat. No. 7,229,022 and US 2008/0314990 an arrayof antennae are installed on a separate substrate to the substratehosting the RFID chips with an identical format. The antenna substrateis then placed over the substrate with the array of RFID chips and thetermination areas of each antenna are manually connected to each chip onthe respective transponder site. It is worth noting that the wire endsof each antenna span a bridge over an opening in the antenna substrateand therefore a distance remains between the wire bridges over theopening and the chip modules on the other substrate. A difficulty withsuch a method is alignment of the wire ends with the terminal areas of achip module, which may require manually aligning the wire ends forinterconnection by hand.

SUMMARY

A method of mounting at least one antenna structure to an inlaysubstrate comprising first forming the at least one antenna structure onan antenna substrate, then transferring the at least one antennastructure to corresponding at least one selected transponder sites on aninlay substrate. The antenna substrate may be in an elongate web form,and the antenna structures may be transferred one-by-one to selectedtransponder sites on the inlay substrate. The inlay substrate may carryan array of antenna structures which may be transferred en masse to acorresponding array of transponder sites on the inlay substrate. Varioustechniques for effecting the transfer are disclosed herein, such as (butnot limited to) using a pick & place machine, causing antenna structuresto be released from the antenna substrate, a contact transfer process.The antenna structure may comprise a wire conductor, electronic ink,conductive paste, electrically charged nano-particles or any conductivemedium. Channels may be formed in the antenna substrate for the antennastructure. A wide trench may be formed in the inlay substrate foraccepting the antenna structure.

An antenna structure may be electrically connected to terminal areas ofthe chip or chip module previously installed at the transponder siteeither during or after the transfer process (in the same or a subsequentstep). The chip module may be joined with an antenna structure while theantenna structure is resident on the antenna substrate, then the antennastructure and chip module transferred together to the inlay substrate.Typically, the chip module will reside in a recess at the transpondersite on the inlay substrate. The antenna structure may reside in a widetrench formed at the transponder site on the inlay substrate.

A plurality of antenna structures may be incorporated into a pluralityof transponder sites by arranging (forming) a plurality of antennastructures with several conductor turns on a synthetic antenna substrate(carrier layer or film), removing the antennas and their terminationends from the antenna substrate by means of die punching, laser cuttingor laminating (contact transfer), and transferring the antennas withtheir termination ends in a fixed and aligned position for mounting ontoor into (a wide trench) an inlay substrate, and subsequently connectingthe aligned termination ends of the antenna structure to terminal areasof an RFID chip (or chip module) disposed on or in (a recess in) theinlay substrate.

A method for arranging an antenna structure on or in an inlay substratebeing monolayer or multi-layer with the antenna structure arranged on anantenna substrate (carrier layer) which is separate from the inlaysubstrate, and antenna structure being removed from said carrier layerbefore placing the antenna structure onto or into (a recess in) theinlay substrate by

-   -   first, mounting a wire conductor on or into the carrier layer        such as by means of ultrasonic embedding, forming an antenna and        routing termination ends of the antenna to pre-defined positions        on the carrier layer for later alignment with the terminal areas        of the RFID chip (or chip module);    -   second, removing the antenna structure from the carrier layer        with its termination ends pre-positioned by application of heat        and pressure, mechanical pressure, punching or laser cutting;    -   third, transferring the antenna structure to the inlay substrate        hosting an RFID chip (or chip module) on or in the inlay        substrate, fixing the antenna structure to the inlay substrate        and connecting the termination ends (connection portions) of the        antenna structure to the terminal areas of the RFID chip (or        chip module) to produce a transponder site.        An overall process may include:    -   a plurality of antenna structures (each as a flat coil having 4        or 5 turns, and two termination ends) may be preformed on the        antenna substrate (carrier film), which may be in the form of a        long web.        -   this enables prefabricating a plurality (such as a row) of            antenna structures independently of preparing another            plurality (such as an array) transponder sites on an inlay            substrate, and later “joining” the preformed antenna            structures to the transponder site (and connecting to the            antenna structures to the chip modules on the transponder            sites).    -   individual antenna structures may be separated (singulated) from        the carrier film by cutting (perforating) around the inner and        outer edges of the antenna structure. This may leave some        “residual” carrier film material between turns of the antenna.        -   connection portions of the antenna wire may be supported            (aligned) by residual carrier film material.        -   potions of the carrier film at the connection portions may            be removed, such as by laser ablation, to facilitate            subsequent bonding of the connection portions to terminals            of the chip module.    -   the singulated antenna structures may be installed on        corresponding transponder sites on an inlay substrate,        one-by-one, until all of the transponder sites are populated        with antenna structures.        -   the turns of the antenna structure, which form a “ring”            (having an outer periphery and an inner periphery), may be            installed in a wide trench which has been formed (such as by            laser ablation) in the inlay substrate.    -   after the antenna is installed on (or in a trench in) the inlay        substrate, connection portions of the antenna structure may be        connected to corresponding terminals (terminal areas) of the        chip module, such as by using conventional bonding techniques.        -   The connection portions may be the ends of the antenna wire            (including for example 1 mm end segments of the antenna            wire), or end portions of the antenna wire (exclusive of the            last few mm of the antenna wire).

An aspect of the current invention is the fact that an antenna structurehaving a number (such as 4 or 5) turns of antenna wire turns is mountedon a carrier layer (substrate) which supports the flat coil shape of theantenna, the pitch between wires or tracks and the rigidity of theassembly.

Other objects, features and advantages may become apparent in light ofthe following descriptions of various embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made in detail to embodiments of the disclosure,examples of which may be illustrated in the accompanying drawing figures(FIGs). The figures are intended to be illustrative, not limiting.Although the invention is generally described in the context of theseembodiments, it should be understood that it is not intended to limitthe invention to these particular embodiments.

Certain elements in selected ones of the figures may be illustratednot-to-scale, for illustrative clarity. The cross-sectional views, ifany, presented herein may be in the form of “slices”, or “near-sighted”cross-sectional views, omitting certain background lines which wouldotherwise be visible in a true cross-sectional view, for illustrativeclarity. In some cases, hidden lines may be drawn as dashed lines (thisis conventional), but in other cases they may be drawn as solid lines.

If shading or cross-hatching is used, it is intended to be of use indistinguishing one element from another (such as a cross-hatched elementfrom a neighboring un-shaded element). It should be understood that itis not intended to limit the disclosure due to shading or cross-hatchingin the drawing figures.

Elements of the figures may (or may not) be numbered as follows. Themost significant digits (hundreds) of the reference number correspond tothe figure number. For example, elements of FIG. 1 are typicallynumbered in the range of 100-199, and elements of FIG. 2 are typicallynumbered in the range of 200-299. Similar elements throughout thefigures (FIGs.) may be referred to by similar reference numerals. Forexample, the element 199 in FIG. 1 may be similar (and possiblyidentical) to the element 299 in FIG. 2. Throughout the figures, each ofa plurality of similar elements 199 may be referred to individually as199 a, 199 b, 199 c, etc. Such relationships, if any, between similarelements in the same or different figures will become apparentthroughout the specification, including, if applicable, in the claimsand abstract.

FIG. 1A is a top view of a transponder site (one of many on an inlaysubstrate or sheet), according to the prior art.

FIG. 1B is a side, cross-sectional view, partially exploded, of a wirebeing mounted to an inlay substrate and bonded to the terminals of atransponder chip, according to the prior art.

FIG. 1C is a side, cross-sectional view illustrating a construction of aleadframe type chip module, according to the prior art.

FIG. 1D is a side, cross-sectional view illustrating a construction ofan epoxy glass type chip module, according to the prior art.

FIG. 1E is a schematic view of an antenna formed with a number of turns,illustrating various “portions” of the antenna structure which may bereferred to in various descriptions.

FIG. 1F is perspective view of a secure document which is an electronicID care, according to the prior art.

FIG. 1G is a perspective view of a secure document which is anelectronic passport cover, according to the prior art.

FIG. 1H is a cross-sectional view of the passport cover shown in FIG.1G.

FIG. 1I is a side, cross-sectional view, partially exploded, of anantenna wire being mounted to an inlay substrate and bonded to theterminals (terminal areas) of an RFID chip (or chip module, also“transponder chip”), which may be the passport cover of FIG. 1H,according to the prior art.

FIG. 2A is a perspective view showing a substrate (which may be an inlaysubstrate) having a recess formed therein, according to an embodiment ofthe invention.

FIG. 2B is a cross-sectional view showing a substrate (which may be aninlay substrate) having a recess formed therein, according to anembodiment of the invention.

FIG. 2C is a partial perspective view showing a substrate (which may bean inlay substrate) having a channel formed therein, and laying a wirein the channel, according to an embodiment of the invention.

FIG. 2D is a partial perspective view showing a substrate (which may bean inlay substrate) having channels, portions of which cross over oneanother, and antenna wire (or portions thereof) in the channels,according to an embodiment of the invention.

FIG. 2E is a cross-sectional view of a substrate (which may be an inlaysubstrate) illustrating a process for forming a channel which isprofiled to receive a wire which is at least partially embedded in thechannel, according to an embodiment of the invention.

FIG. 2F is a top schematic view of a recess in a substrate, and channelsextending from (opposite) edges of the recess.

FIG. 2G is a cross-sectional view illustrating mounting an antenna wirein a channel, according to an embodiment of the invention.

FIG. 2H is a cross-sectional view illustrating an antenna wire mountedin a channel, according to an embodiment of the invention.

FIG. 2I is a cross-sectional view illustrating a flowable, conductivematerial being applied on a surface of a substrate to fill a channel,according to an embodiment of the invention.

FIG. 2J is a cross-sectional view illustrating a further step in thetechnique of applying a flowable, conductive material on a surface of asubstrate to fill a channel, according to an embodiment of theinvention.

FIG. 2K is a cross-sectional view illustrating a flowable, conductivematerial being applied to fill a channel in a layer of adhesive,according to an embodiment of the invention.

FIG. 2L is a cross-sectional view illustrating a further step in thetechnique of applying a flowable, conductive material to an adhesivelayer to fill a channel, according to an embodiment of the invention.

FIG. 3A is a partial perspective view of a technique for joining sheetsin to a web, according to an embodiment of the invention.

FIG. 3B is a cross-sectional view of a technique for thinning an edgeregion of a substrate, according to an embodiment of the invention.

FIG. 3C is a partial perspective view of a technique for forming raisedfeatures (such as studs) in an edge region of a substrate, according toan embodiment of the invention.

FIG. 3D is a partial perspective view of a technique for formingfeatures such as holes for receiving studs in an edge region of asubstrate, according to an embodiment of the invention.

FIG. 3E is a cross-sectional view of a technique for forming channels ina substrate, such as for receiving individual turns of an antennastructure, according to an embodiment of the invention.

FIG. 3F is a cross-sectional view of a technique for forming a widetrench in a substrate, such as for receiving an entire antennastructure, according to an embodiment of the invention.

FIG. 3G is a top view of a portion of an inlay substrate showing arecess for receiving a chip module (CM) and channels extending fromedges of the recess, according to an embodiment of the invention.

FIG. 3H is a cross-sectional view of a secure document such as anelectronic passport cover, according to an embodiment of the invention.

FIG. 3I is a top view of an inlay for forming a plurality of securedocuments such as electronic passport covers, according to an embodimentof the invention.

FIG. 3J is a cross-sectional view of a secure document such as anelectronic passport cover, according to an embodiment of the invention.

FIG. 3K is a cross-sectional view of a step in a technique for applyingadhesive to a layer of passport cover material, according to anembodiment of the invention.

FIG. 3L is a cross-sectional view of a further step in a technique forapplying adhesive to a layer of passport cover material, according to anembodiment of the invention.

FIG. 3M is a cross-sectional view of a further step in a technique forapplying adhesive to a layer of passport cover material, according to anembodiment of the invention.

FIG. 3N is a cross-sectional view of a further step in a technique forapplying adhesive to a layer of passport cover material, according to anembodiment of the invention.

FIG. 4 is a diagram of a selected on of many transponder sites on aninlay substrate comprising an RFID chip (or chip module) disposed in arecess in the inlay substrate, and an antenna structure also disposed onthe inlay substrate and connected by its termination ends (connectionportions) to corresponding terminal areas (terminals) of the RFID chipmodule, illustrating an embodiment of the invention. FIG. 4 isillustrative of a “combination” of FIGS. 4A and 4B.

FIG. 4A is a diagram illustrating the formation and arrangement ofantenna structures on an antenna substrate (such as film or carrier),according to an embodiment of the invention.

FIG. 4B is a diagram illustrating preparation transponder sites on aninlay substrate, for receiving the antenna structures of FIG. 4A,according to an embodiment of the invention.

FIG. 4C is a diagram or cross-sectional view illustrating a techniquefor transferring an antenna structure from an antenna substrate to aninlay substrate, according to an embodiment of the invention.

FIG. 5A is a diagram or cross-sectional view illustrating a techniquefor transferring an antenna structure from an antenna substrate to aninlay substrate, according to an embodiment of the invention.

FIG. 5B is a diagram or cross-sectional view illustrating a techniquefor transferring an antenna structure from an antenna substrate to aninlay substrate, according to an embodiment of the invention.

FIG. 5C is a diagram illustrating a technique for forming a plurality ofantenna structures on an antenna substrate, prior to transferring theantenna structures from the antenna substrate to an inlay substrate,according to an embodiment of the invention.

FIG. 5D is a diagram or cross-sectional view illustrating a further stepin the technique for transferring antenna structures from an antennasubstrate to an inlay substrate, according to an embodiment of theinvention.

FIG. 5E is a diagram or cross-sectional view illustrating a further stepin the technique for transferring antenna structures from an antennasubstrate to an inlay substrate, according to an embodiment of theinvention.

FIG. 6A is a diagram or cross-sectional view illustrating a techniquefor forming a plurality of antenna structures on an antenna substrate,prior to transferring the antenna structures from the antenna substrateto an inlay substrate, according to an embodiment of the invention.

FIG. 6B is a diagram or cross-sectional view illustrating a further stepin the technique for transferring antenna structures from an antennasubstrate to an inlay substrate, according to an embodiment of theinvention.

FIG. 6C is a diagram or cross-sectional view illustrating a further stepin the technique for transferring antenna structures from an antennasubstrate to an inlay substrate, according to an embodiment of theinvention.

FIG. 6D is a diagram or perspective view illustrating a technique forforming a plurality of antenna structures on an antenna substrate, priorto transferring the antenna structures from the antenna substrate to aninlay substrate, according to an embodiment of the invention.

FIG. 6E is a diagram or perspective view illustrating a further step inthe technique for transferring antenna structures from an antennasubstrate to an inlay substrate, according to an embodiment of theinvention.

FIG. 6F is a diagram or cross-sectional view illustrating a further stepin the technique for transferring antenna structures from an antennasubstrate to an inlay substrate, according to an embodiment of theinvention.

DETAILED DESCRIPTION

Various “embodiments” of the invention (or inventions) will bediscussed. An embodiment is an example or implementation of one or moreaspects of the invention(s). Although various features of theinvention(s) may be described in the context of a single embodiment, thefeatures may also be provided separately or in any suitable combination.Conversely, although the invention(s) may be described herein in thecontext of separate embodiments for clarity, the invention(s) may alsobe implemented in a single embodiment.

The relationship(s) between different elements in the figures may bereferred to by how they appear and are placed in the drawings, such as“top”, “bottom”, “left”, “right”, “above”, “below”, and the like. Itshould be understood that the phraseology and terminology employedherein is not to be construed as limiting, and is for descriptivepurposes only.

The invention relates generally to inlays and techniques for making theinlays, including technical features and security features. As usedherein, an “inlay” may be a single- or multi-layer substrate containingHF (high frequency) and/or UHF (ultra-high frequency) radio frequencyidentification (RFID, transponder) chips and/or modules. These inlaysmay be used in secure documents, such as, but not limited to, electronicpassports (ePassports) and electronic ID (eID) cards.

Some Embodiments of the Invention

Various embodiments of the invention will be presented to illustrate theteachings of the invention(s). In the main, examples of electronicpassport covers with inlay substrates having leadframe modules may beused to illustrate the embodiments. It should be understood that variousembodiments of the invention(s) may also be applicable to other securedocuments containing electronics (such as RFID and antenna), such aselectronic ID cards. Secure documents may also be referred to as“electronic documents”. In the main hereinafter, secure documents whichare passport inlays, typically cold laminated (with adhesive), arediscussed.

The following embodiments and aspects thereof may be described andillustrated in conjunction with systems, tools and methods which aremeant to be exemplary and illustrative, not limiting in scope. Specificconfigurations and details may be set forth in order to provide anunderstanding of the invention. However, it should be apparent to oneskilled in the art that the invention(s) may be practiced without someof the specific details being presented herein. Furthermore, well-knownfeatures may be omitted or simplified in order not to obscure thedescriptions of the invention(s).

Forming Recesses in a Substrate

A method of forming a recess in an inlay substrate for a transponderchip module may comprise: forming a recess for the RFID transponder chip(or chip module) in a surface of an inlay substrate, wherein the recessextends at least partially through the inlay substrate. A laser may beused to form the recess by ablating material from the substrate. Thelaser may be scanned across the surface of the substrate to form therecess. The substrate may comprise Teslin™.

FIG. 2A illustrates an exemplary process 200 of forming a recess(opening, window) 206 in an inlay substrate 202, using a laser. Theinlay substrate 202 may be a single layer of Teslin™ (for example),having a thickness “t” of 356 μm. A typical size (width dimensions) forthe recess 206, to accommodate a chip module with a lead frame, may beapproximately 5 mm×8 mm. The recess may extend completely through theinlay substrate, resulting in a “window-type” recess. The recess mayextend only partially, such as 260 μm through the inlay substrate,resulting in a “pocket-type” recess (FIG. 1B illustrates a pocket-typerecess).

The Laser emits a beam (dashed line), targeted at the substrate, toablate material from the substrate to form the recess. The beam may havea diameter of approximately 15 to 60 μm. The beam may be scanned backand forth, traversing in one direction entirely across the recess area,turning around, and traversing back across the recess area, like plowinga field. Many passes may be required to carve out the entire area anddepth of the recess, given that the beam diameter is typically much(such as 10-100 times) smaller than the length or width of the recess.As is known, the beam may be scanned, in any suitable manner, such aswith scanning minors. Also, the intensity of the beam may be controlledor modulated to control the penetration into the substrate. For example,a pulse-width modulated beam may be used. The Laser may be a UV laser(355 nm) with a power ranging from 15 to 50 watts.

The process of using a laser in this manner, rather than (for example) aconventional rotating milling tool, may be referred to as “lasermilling”. The technique described herein may be particularly beneficialfor applications where it is desired to form a “pocket” type recesswhich intentionally does not extend all the way through the substrate orsheet (in other words, the recess or pocket extends only partiallythrough the substrate). Mechanical milling can be difficult. On theother hand, laser milling can be very effective for Teslin™ andpolycarbonate (PC) substrates. For PVC, laser milling is less effective.

The recess (opening) 206 formed in the inlay substrate 202 of FIG. 2A isshown extending completely through the inlay substrate 202, but mayextend only partially through the substrate. The recess may havestraight sidewalls, or it may be “stepped”.

A chip module (such as 108) may be disposed in the recess so as to besubstantially contained within the inlay substrate (as illustrated inFIG. 1B), without protruding from the surface there of, and withoutcreating a “bump” in an overlying layer, such as the cover layer oroverlay layer.

FIG. 2B shows forming a stepped pocket-type recess 206 b in a singlelayer of material, such a layer of Teslin™ for an inlay substrate 202 b,using laser ablation. This may be a two-step process comprising:

-   -   first laser milling a central area (such as between “b” and “c”)        to a depth (“d2” minus “d1”) partially through the substrate,    -   then continuing laser milling the entire area (such as between        “a” and “d”) to create a recess extending to a depth “d1”        partially through the substrate in a peripheral area, and        extending in the central area to a depth “d2” deeper into (but        not completely through) the substrate.

Alternatively:

-   -   first laser milling the entire area (between “a” and “d”) to a        first depth (“d1”)    -   then laser milling only the central area (between “b” and “c”)        to a second depth (“d2”).

Forming Channels in a Substrate

The antenna wire may be mounted to the surface of an inlay substrate byultrasonically embedding (countersinking) it into the surface of theinlay substrate. Ideally, the antenna wire would be fully embedded sothat it is flush or below the top surface of the inlay substrate. Forapplications such as driver's license or passports, it is generally notdesirable that the wire be less than fully embedded and extend(protrude) above the surface of the inlay substrate. Rather, it isdesirable that the antenna not be visible (known as “witnessing thewire”) to the user in the end product.

With ultrasonic embedding, the wire may become only partially embedded,such as approximately half its diameter. In Teslin™, it is verydifficult to ultrasonically embed an antenna wire. Self-bonding wire maybe used, and after mounting the wire on the substrate (and forming theturns of the antenna) it may be pressed into the substrate, using heatand/or pressure, through a lamination process

In order to facilitate fully embedding the wire, a “channel” (or“groove”, or “trench”) may be formed in the surface of the inlaysubstrate to accept the antenna wire. Then, the antenna wire may then belaid (inlaid, pressed, sunk) into the channel.

The depth of the channel should be at least a substantial portion of thediameter of the wire. Alternatively, the channel may be less deep thanthe diameter of the wire and, as the wire is laid down into the groove,it may be pressed further into the substrate.

The width of the channel may be approximately equal to the diameter ofthe wire. Or, the channel may be narrower than the diameter of the wire,such as approximately 95% of the diameter of the wire, to facilitate an“interference” fit, securely holding the wire in position for subsequenthandling.

Generally, the wire typically has a circular cross-section (but may haveother cross-sections, such as a ribbon wire), and the groove may have asubstantially rectangular cross-section. The wire may be self-bondingwire having an adhesive coating.

By first forming channels to accept the wire in the substrate, severaladvantages may be realized, such as eliminating the need for thepressing operation associated with ultrasonic embedding of the antennawire.

FIG. 2C illustrates a technique 220 using a laser to form a channel(groove, trench) 222 in a surface of an inlay substrate 202. This is anexample of removing material to form the channel. The laser is shownmoving from left-to-right in the figure.

A wire 210 is shown being laid down (installed) into the channel 222,from left-to-right, and may be urged into the channel by a simplepressing tool (or wheel) 224. The wire 210 may be laid into the channelduring formation of the channel, by following after (to the left of) thelaser a distance “u”. The wire may be installed after the channel iscompleted.

The wire 210 may be a self-bonding (coated, self-adhering wire). Inconjunction (such as simultaneous) with laying the wire in the groove(channel), the wire may be warmed thermally (such as with heat),chemically activated (such as with alcohol), or warmed electrically(such as by passing a current through the wire. The pressing tool 224itself may be heated. Or, a separate heating element 226 may beprovided, such as a nozzle directing hot air onto the wire eitherimmediately before (to the right of) or after (to the left of, as shown)the pressing tool 224. The heating element 226 may be a laser operatingin a range to heat the wire sufficiently to activate the adhesivecoating.

Although only one straight channel is shown, a 2-dimensional (x-y)groove pattern may thus be formed in (extending into) the top surface ofthe inlay substrate, for accepting an antenna wire having a number ofturns or coils. A single channel (portions of an overall channel) mayextend from adjacent the chip module (such as from an edge of the recessreceiving the chip module), across the surface of the substrate todefine a pattern for the turns of the antenna, returning to adjacent thechip module (such as to an opposite edge of the recess receiving thechip module).

FIG. 2D illustrates a method of forming a pattern of channels (orportions of an overall channel) in a substrate 202 to accommodate anantenna wire in a situation where the wire needs to cross over itself(such as shown in FIG. 1A), in which case insulated wire may beappropriate. (FIG. 4 of U.S. Pat. No. 6,088,230 and FIG. 5 of 6,233,818show an antenna pattern with crossovers. Typically, a short circuit maybe avoided at the crossover by using insulated wire, and the sonotrodemay be switched off in the vicinity of the crossover).

The use of channels for accepting the antenna wire can be advantageousfor mounting an antenna wire in a pattern that requires the antenna wireto cross over itself, without shorting. (The use of insulated wire mayavoid short-circuiting, but channels may still be desirable for otherreasons, including that a sonotrode is generally not necessary forlaying the antenna wire in the channel.) For example:

-   -   a first portion of the antenna wire may be “fully” embedded in a        channel, without protruding above the surface of the substrate.        The channel may be made deeper than the wire at the point where        crossover will occur to ensure that the antenna wire is indeed        fully embedded.    -   Then, a second portion of the antenna wire which crosses over        the first portion may be laid on the surface of the substrate.

Alternatively,

-   -   a first portion of the antenna wire is fully embedded in a first        channel (or portion of the overall channel) which is very deep        where the second portion of the antenna wire will be crossing        over the first portion of the antenna wire. (The first, deep        portion of the channel may be approximately twice as deep as the        second, shallow portion of the channel.)    -   the second portion of the antenna wire is embedded in a channel        (or portion of the overall channel) which is “normal” depth for        accepting a wire conductor    -   The depth of the first channel portion is sufficient that the        second portion of the wire crossing over the first portion of        the antenna wire does not short thereto.

FIG. 2D illustrates the latter variation where there is a shallowchannel portion 222 a crossing over a deep channel portion 222 b. Thechannels 222 a and 222 b may be portions of a single overall channel inthe substrate 202 defining the antenna pattern. A second portion 210 bof the antenna wire crosses over the first portion 210 a of the antennawire.

A first portion 210 a of the antenna wire 210 is disposed in the deepportion 222 b of the channel, and is shown in dashed lines. A secondportion 210 b of the antenna wire is disposed in the shallow portion 222a of the channel. In this manner, the second portion of the antenna wiremay pass over the first portion of the antenna wire without contactingit. Some exemplary dimensions are:

-   -   the wire may have a diameter of 80 μm    -   the channel(s) may have a width of 100 μm    -   the shallow channel may have a depth of 100 μm    -   the deep channel may have a depth of 200 μm    -   the substrate may have a thickness of 350 μm

Generally, insulated and/or self-sticking (self-bonding) wire would beused. But using these techniques, un-insulated (bare) wire may also beused, again avoiding the necessity of removing insulation fromconnection portions of the wire.

Once the channel is created, the wire conductor (which may be aself-bonding wire) can be installed into the channel and simultaneouslythermally or chemically activated (with laser, hot air, with alcohol),so that the adhesive layer of the self-bonding wire sticks to the wallsof the channel.

If the diameter of the laser beam is sufficiently wide (correspondingwith the desired width of the channel), and has sufficient fluence (topenetrate to the desired depth of the channel), the channel may beformed with one pass of the laser. To enhance the quality (such astexture) of the structure of the channel, it may be advantageous to usean ultrafast laser (in the picosecond or femtosecond range) using a lowfluence above the threshold fluence and removing material layer by layer(several passes). At high fluence, there is a trade-off in rate ofmaterial removal and the quality of etching.

Multiple passes of the laser may be scanned across the length of thechannel to increase the width and/or depth of the channel, each pass ofthe laser ablating the channel to an increased depth, in an iterativemanner. For example, several passes of the laser may be used to form achannel having an overall depth of 80 μm by ablating a 30 μm wide, 5-10μm deep amount of material with each pass. For example, to form achannel having a width of approximately 100 μm (such as 97 μm) and anoverall depth of 80 μm, multiple passes of a laser having a beam widthof 30 μm may be used. In one pass, the 30 μm diameter beam may ablateapproximately a 70 μm wide area, to an average depth of approximately 5μm. In subsequent passes, the beam may be overlapped with a previouslyablated area, such as with a 50% overlap. In three or four passes, the100 μm wide channel may be ablated.

Generally, the laser beam may be directed to the surface of a substratevia a galvanometer. The laser beam ablates the material line for linewith an overlap of about 50-60% to get the best surface finish.

The width of the laser beam (hence, the resulting width of ablation) maybe modified optically (beam shaping—such as with lenses, using a mask orchanging the beam shape) to have a narrower laser beam width. Thepenetration of the laser beam (hence, the resulting depth of ablation)may be modified by changing the fluence and or repetition rate of thelaser.

The channel may be formed with many (several) passes of the laser, eachpass forming a portion of the overall channel. For example, a first passof the laser may form a first portion of the channel having a width ofapproximately 100 μm (such as 97 μm) and a depth of 5 μm (dependent onthe laser pulse energy and repetition rate). A second and severalsubsequent aligned passes of the laser may extend the previously formedportion(s) of the channel deeper, maintaining the same 97 μm width,until an intermediate channel depth of 45 or 50 μm is achieved—half ofthe desired overall depth of the channel. Then, maintaining alignment,in subsequent several passes the width of the laser beam may be lessenedwith each pass, resulting in a bottom portion (half) of the channeltapering down. In this manner, a channel can be created which has aprofile (cross-section) similar to that of the wire. This may increasethe opportunity for the antenna wire to stick to the walls of thechannel.

FIG. 2E illustrates a method of forming a channel in a substrate withmultiple passes of the laser, the resulting channel having a taperedprofile. A first path “P1” is shown over a central portion of thechannel. A second path “P2” is shown over a left portion of the channel.A third path “P3” is shown over a right portion of the channel. Theorder of these paths can be different.

Notice that the channel in the figure is “stepped”. This representsmaking several passes with the laser, at a few (such as three) widthwisepositions (paths P1,P2,P3). Each pass of the laser may only remove 5 μmof material, in which case 20 passes would be needed to achieve a depthof 100 μm at any given position.

The channel can be rectangular (straight sidewalls). The channel can betapered, or U-shaped. In FIG. 2E, the top half (such as upper 50 μm) ofthe channel has straight sidewalls, and the lower half (such as bottom50 μm) of the channel decreases in width as the depth increases, therebythe sidewalls are tapered, and approximate the semicircular profile ofthe bottom half of the antenna wire (shown in dashed lines). Thisincreases the contact area between the sidewalls of the channel and theantenna wire, which will enhance adhesion of a self-bonding wire in thechannel.

Alternatively, masks may be used to block portions of the laser beam andeffect a similar stepwise decrease in width accompanying increase indepth.

Some exemplary operating conditions for the laser may be:

-   -   operating the laser at a pulse repetition rate of 30-40 kHz (one        pulse every approximately 30 microseconds)    -   the duration of each pulse may be approximately less than 10        picoseconds

A low duty cycle (relatively short pulse in a relatively long interval)may be advantageous for “cold ablation”, where the material is notsignificantly heated.

The polymer substrate may be porous, facilitating the laser ablation,and the ablation may be performed in an inert atmosphere. Debris can beremoved through a suction system (not shown).

FIG. 2F illustrates that channels for receiving an antenna wire mayextend from edges, such as opposite side edges of a recess for receivinga chip module.

Forming Channels in an Adhesive Layer

FIGS. 2G and 2H illustrate that a channel 272 forming an antenna patternmay be formed in a layer 274 of adhesive on the surface of an inlaysubstrate 276 (or a layer of a multi-layer inlay substrate), and a wire278 may be mounted therein using a tool 280. For example, the adhesive274 may be 80 μm thick glue. The channel (groove, trench) 272 may be,for example, 60-80 μm deep. The channel 272 may go all the way throughthe adhesive 274, and further into the substrate. The channel 272 mayextend only partially through the adhesive 274, as indicated by thedashed line at the bottom of the channel 272.

The adhesive 274 may be polyurethane. Polyurethane, once beyond its“open time”, goes hard, making it ideal for channel (groove, trench)formation. Later, for laminating, it may be reactivated with a heatsource, such as an infrared light. Hence, the adhesive may be appliedsufficiently in advance of channel formation, such as 1-10 minutes (forexample) before, to facilitate channel formation.

Filling Channels in a Substrate

FIG. 2I illustrates a substrate 276 having a channel (groove, trench)262 formed in a top surface thereof, and a quantity of flowable,conductive material 244 applied on the surface. Some of the material 244may be in the channel 262. The conductive material 244 may be viscous,such as metallic powder, conductive glue (see list above). A squeegee246 is shown positioned above the material 244. The squeegee 246 will belowered (see arrow) so as to be substantially in contact with the topsurface of the substrate 276.

FIG. 2J illustrates that as the squeegee 246 is advanced (see arrow), itforces the conductive material 244 into the channel 262. Residualconductive material 244 is substantially cleared from the surface of thesubstrate 208, but an additional cleaning step may be added.

Filling Channels in an Adhesive Layer

FIGS. 2K and 2L are similar to FIGS. 2I and 2J, and show that thechannels can be formed in a layer 280 of adhesive on the surface of thesubstrate 276 and filled with conductive material 244. In this example,the adhesive 280 is 80 μm thick glue. The channel (groove, trench) 262may be, for example, 60-80 μm deep. The channel 262 may go all the waythrough the adhesive 280, and further into the substrate 276.

The adhesive 280 may be polyurethane. Polyurethane, once beyond its“open time”, goes hard, making it ideal for trench formation. Later, forlaminating, it may be reactivated with a heat source, such as aninfrared light. Hence, the adhesive may be applied sufficiently inadvance of channel formation, such as 1-10 minutes (for example) before,to facilitate channel formation.

Adhesive Coating of an Electronic Passport Cover

This embodiment relates to inlay substrates adhesively attached topassport cover material to produce an intermediate product used in theproduction of security documents such as electronic passports.

A “security document” such as an electronic passport (ePassport) maycomprise an “inlay substrate” (or “inlay laminate”) which is typically asheet (or layer) of material such as Teslin™, with a Radio FrequencyIdentification (RFID) chip module and corresponding antenna mountedtherein, with an additional “cover layer” (or “cover material”), such asPVC-coated paper, cloth or synthetic leather laminated (or joined)thereto. The production of an electronic passport cover involves theadhesive attachment of an inlay substrate with a cover layer.

The inlay format is typically “3up” (for making three passport covers ona single sheet of inlay material), and is generally planar andrectangular, having exemplary overall dimensions of 404.81 mm×182.56mm×0.70 mm (thick).

The material for the cover layer may be PVC coated offset board oracrylic coated cotton, embossed and thermo-resistant. In the case of thefabric material, the backside coating can be water-base coated(aqueous/non-solvent), synthetic coated or have no coating. The frontside coating can have two base coatings and one top coating of acrylic.An alternative to acrylic coating is peroxylene-based coating(nitrocellulose). The fabric can have a strong bias (diagonal) in theweave (drill weave as opposed to linear weave) which gives it hightensile strength and restricts the elongation. The leather embossinggrain can have the resemblance of the skin of a kid goat or sheep(skiver) and is applied using an embossing cylinder drum at a pressureof 60 tons at around 180 degrees Celsius (° C.). Because of the frontand backside coatings the fabric is not porous.

The material for the cover layer may be a cloth product, with chemistryin the coatings and a leather-like appearance to the cloth, such as byHolliston Inc. (905 Holliston Mills Road, Church Hill, Tenn. 37642;www.holliston.com)

The material for the inlay substrate may be Teslin™, a waterproofsynthetic film, single-layer, uncoated with a thickness of 356 microns.

Typically, the cover material is supplied in web form and coated with anadhesive with a short opening time, before laminating with an inlaylayer. Such web coating and lamination systems are supplied by Nordson.

However, because of the nature of the fabric material and the supplier'smanufacturing process, they are many defects such as blemishes,scratches, cross directional lines, untextured surface, bent edges anddents in the cover layer when supplied in web form. The sorting of thesedefects is best done by the supplier of the cover layer, but this limitsthe format of the deliverable cover layer to sheets.

An overall view of a passport cover is shown in FIG. 1G which shows acover layer laminated to an inlay substrate (the chip module and antennastructure are omitted from the view, for illustrative clarity, havingbeen shown elsewhere).

According to an embodiment of the invention, a method is described forconverting individual sheets of cover material and into an endless webto be coated with an adhesive and then cutting the coated material intosheets for lamination with inlay substrates to produce electronicpassport covers.

In one embodiment of the invention, the sheets of cover material areoverlapped at each end by approximately 1 cm. The overlapping sheets ateach end are bonded together, punctually (at distinct points) orcontinuously, using a hot stamp or an ultrasonic tool. The covermaterial bonds easy because of the acrylic coating.

FIG. 3A shows two (of several) individual cover sheets being joinedend-to-end, as follows:

-   -   a first Holliston fabric sheet 302 having a right (as viewed)        end    -   a second Holliston fabric sheet 304 having a left (as viewed)        end    -   the right end of the sheet 302 overlaps the left end of the        sheet 304 by approximately 1 cm (the right end portion of the        sheet 302 is atop the left end portion of the sheet 304)    -   an ultrasonic tool 310 may be used to bond (“weld”) the top        sheet 302 to the bottom sheet 304 in an “overlap area” (right        end portion of left sheet 302 overlapping left end portion of        right sheet 304).    -   The “weld” points may be approximately 2 cm apart from one        another (alternatively, the weld may be continuous, not        punctual)    -   the sheets 302 and 304 are being fed and conveyed from left to        right (as viewed)    -   a roller 320 is used for applying adhesive (not shown) to the        top surface of the joined sheets    -   another roller 322 is disposed under the joined sheets, opposite        the roller 320, to support the sheets during adhesive        application.    -   additional rollers and/or a conveyor belt may be incorporated,        as illustrated

A given Holliston fabric sheet (302 or 304) may be 360 μm thickincluding an acrylic coating of a few microns on its top (as viewed)surface.

The sheets 302, 304 may each measure 300 mm long (left to right), and200 mm wide.

The sheets (302, 304) may be another synthetic material such as Teslin™

Many sheets may be joined in this manner to make a web (roll). Forexample, 100 sheets each 30 cm long to form a continuous web 30 m long.

In use (e.g., joining to an inlay substrate), the overlap area may beexcised (not used in the final product).

Joining Sheets of Material Together

FIG. 3B shows a chip module 308 installed in a recess 306 of an inlaysubstrate 302. A side extension, or edge region 304 of the substrate 302may be thinned by laser ablation such as to a fraction of thesubstrate's original thickness, such as to approximately 50% of theoriginal thickness. A laser is shown ablating from the top (as viewed)surface of the substrate, but it will be understood that the ablatingcould occur from the bottom surface of the substrate 302, or from boththe top and bottom surfaces of the substrate 302. By thinning thesubstrate at an edge region, an “overlap joint” may be made with anotherelement, such as a flap of plastic material 330 (shown in dashed lines).

FIG. 3C shows that laser ablation may be used to create “studs” 332along the edge region 304 of the substrate 302 for inserting into holesof a separate element (not shown, such as a plastic flap).

FIG. 3D shows that laser ablation may be used to create holes 334 alongthe edge region 304 of the substrate 302 for receiving mating studs of aseparate element (not shown, such as a plastic flap).

The technique shown in FIGS. 3B,C,D may be useful in a method formanufacturing a booklet, such as for instance an ID booklet, whichbooklet is provided with a number of sheets of paper and a covermaterial, each sheet having a front and a reverse side, each sidecomprising two pages, which method comprises connecting the sheets ofpaper to each other along a line between the pages, attaching the covermaterial to the outside of the booklet, and making a fold in the sheetsof paper to form a back of the booklet, such as is disclosed in U.S.Pat. No. 6,213,702, incorporated by reference herein.

Generally, laser ablation may be used to thin an entire region of thesubstrate, and to form 3-dimensional features such as studs in a thinnedregion of the substrate, or to form holes in a thinned region of thesubstrate. Each of these would constitute a “mechanical feature” of aninlay substrate which may be used to create an interlocking clampbetween a flap and a data page inlay using laser ablated studs andrecesses.

Wide Channels (Trenches) for Accepting an Antenna Structure

As described hereinabove, channels may be formed for accepting anantenna wire. According to an embodiment of the invention, a wide“antenna trench” (channel, trench, groove) may be formed in the inlaysubstrate, the trench having a width which is sufficient to accept theseveral (4 or 5) turns of an the antenna structure. The antennastructure may be formed “off line” (other than on the inlay substrate,such as by radial coil winding, winding a coil according to the flyerprinciple, scribing or placing a wire on an intermediate medium andforming a coil to be transferred, forming a coil on a spindle (mandrel),punching a metallic foil to form parts of a coil etc.), and then isplaced into the wide antenna trench. After installing the antennastructure in the wide antenna trench, connection portions (ends or endportions) of the antenna wire may be connected to the terminals(terminal areas) of the chip module. The wide antenna trench may beformed using laser ablation, and may extend from edges of a recess(which also may be formed by laser ablation) for the chip module.

This technique bears some resemblance to U.S. Pat. No. 5,809,633(Mundigl), but because there is a wide trench, it is not necessary topress the antenna into the substrate.

FIG. 3E shows four individual portions 310 a, 310 b, 310 c, 310 d of anantenna wire (310) being inserted into corresponding four individualportions 312 a, 312 b, 312 c, 312 d of a channel (312) or channels in asubstrate 302. The substrate 302 may be an inlay substrate for atransponder. Each portion of the wire may be inserted (laid)sequentially (turn-by-turn) into the corresponding channel portion asthe turns of the antenna are formed on the substrate, such as using asonotrode tool (such as in the manner that a sonotrode tool is used inU.S. Pat. No. 6,233,818 to lay an antenna wire on an inlay substrate).The channel may be formed by laser ablation.

FIG. 3F shows a single, wide antenna trench (or groove) 422 formed in asubstrate 402. The substrate 402 may be an inlay substrate for atransponder. The antenna trench 422 may be several times wider than thediameter (or cross-dimension) of the wire (the wire need not have around cross-section), so that the single wide antenna trench canaccommodate the multiple turns of an antenna structure. The trench(which is essentially a wide channel) may be formed by laser ablation.

An antenna structure (320) having four turns 320 a,b,c,d of antenna wire(a flat coil) is shown being disposed (installed into) the wide antennatrench 322. Typically, the turns of the antenna structure would bespaced slightly apart from one another (rather than touching).

The antenna trench may have a width (across the page) which is muchwider than the cross-dimension (diameter) of the antenna wire. For fourturns of antenna wire, the antenna trench should be at least 4 timeswider than the diameter of a given wire (more like 5 times as wideallowing for some spacing between adjacent turns of the wire).

The antenna trench 322 may be “much wider”, such as at least 2 timeswider than the cross-dimension (diameter) of the antenna wire (or thelike) so that it can accommodate at least two turns of a flat antennacoil structure disposed in the antenna trench. For example, four turnsof 80 μm wire, spaced 40 μm apart from one another, in a 450 μm wideantenna trench 322.

The wide antenna trench should have a depth (into the substrate, from afront surface thereof) which is approximately equal to the diameter ofthe wire so that the flat coil of the antenna structure will be recessedat least flush within the trench, not protruding above the front surfaceof the substrate after it is installed.

The turns of the antenna structure may be laid (scribed) into the trenchsequentially (turn-by-turn) using a sonotrode tool (such as in themanner that a sonotrode tool is used in U.S. Pat. No. 6,233,818 to layan antenna wire on an inlay substrate). Alternatively, the antennastructure can be preformed, and disposed as a single unit into the widetrench. In conjunction with laying the antenna in the trench (whetherturn-by-turn or as a single unit), connection portions (ends, endportions) of the antenna being formed in the trench may be connected toterminals of the chip module.

Connection portions (ends, end portions) of a preformed antennastructure wire may be connected to terminals of the chip module (notshown) prior to installing the antenna in the trench (in such a case,the antenna and chip module would be installed together, as in U.S. Pat.No. 5,809,633 Mundigl), or the antenna wire may be connected to theterminals of a chip module previously installed in the substrate.

Glue may be dispensed in the antenna trench the width of an antenna, andwire embed or place an antenna into the antenna trench.

The trench to accept an antenna structure may be partially filled withadhesive. Alternatively, a layer of adhesive could be disposed over theentire area of the inlay substrate covering the trench for the antennastructure and the recess for the chip module. In placing the chip orchip module in its laser ablated recess, the adhesive would act as ananti-fretting medium to reduce the risk of micro-cracking especially inpolycarbonate (PC) cards.

As an alternative to using wire, copper foil(s), such as punched(stamped) metallic foils may be laid into the antenna trench. A ribbonmay be used.

A process involving the selective deposition and formation of copperlayers is described athttp://www.kinegram.com/kinegram/com/home.nsf/contentview/˜kinegram-rfid

FIG. 3G shows that a wide antenna trench may be contiguous with (extendfrom the edges of) a recess for the chip module, in a manner similar tothat shown (for a single wire channel) in FIG. 2F. However, the trenchneed not be wide where it meets the recess, since typically only onewidth of the wire will be coming onto the chip module (such as one endof the antenna wire one on each of two opposite sides of the chipmodule), such as is illustrated in FIG. 1A. The trench may be wide whereit needs to be, and narrower where appropriate, the width of the trenchat a given location depending on what is going to be inserted into thetrench, which may be an irregularly shaped object, such as an antennastructure having a main body portion (the turns) and termination endsextending from the main body portion (see for example FIG. 4).

The antenna wire may be insulated and/or self-binding. If usinginsulated wire, the insulation (and self-bonding) layers may be removed,such as by using an excimer laser (UV), at the positions forinterconnection (end portions, or connection portions of the antennawire). For an antenna having an overall length of 114 cm, insulation maybe removed every 114 cm. To avoid oxidization, the bare (copper)portions of the wire may be coated with a very thin layer of insulationwhich may evaporate at low temperature during thermo compressionbonding.

The two connection portions (terminal ends, ends, end portions, or thelike) of the antenna may be connected to opposing sides of the RFIDchip, so as to reduce the abrasion of the antenna wire between theleadframe and the substrate. Conventionally, each wire end of theantenna is embedded into the substrate on each side of the terminal area(one side of the leadframe) creating tension of the wire end at theinterface between the leadframe and the substrate, resulting in thegradual cutting of the wire end at the positions of the leadframe.

Adhesive Coating Using a Transfer Substrate

This embodiment relates to inlay substrates adhesively attached topassport cover material to produce an intermediate product used in theproduction of security documents such as electronic passports. Inparticular, the invention describes a technique (process) for smoothadhesive coating of and having a smooth adhesive finish on theelectronic passport cover material, especially in the hinge area, tofacilitate the adhesive attachment of the passport booklet to the inlaycover.

A “security document” such as an electronic passport (ePassport) maycomprise an “inlay substrate” (or “inlay laminate”) which is typically asheet (or layer) of material such as Teslin™, with a Radio FrequencyIdentification (RFID) chip module and corresponding antenna mountedtherein, with an additional “cover layer” (or “cover material”), such asPVC-coated paper, cloth or synthetic leather laminated (or joined)thereto. The production of an electronic passport cover involves theadhesive attachment of an inlay substrate with a cover layer.

The inlay format is typically “3up” (for making three passport covers atonce), and is generally planar and rectangular, having exemplary overalldimensions of 404.81 mm×182.56 mm×0.70 mm (thick).

The material for the cover layer may be PVC coated offset board oracrylic coated cotton, embossed and thermo-resistant. In the case of thefabric material, the backside coating can be water-base coated(aqueous/non-solvent), synthetic coated or have no coating. The frontside coating can have two base coatings and one top coating of acrylic.An alternative to acrylic coating is peroxylene-based coating(nitrocellulose). The fabric can have a strong bias (diagonal) in theweave (drill weave as opposed to linear weave) which gives it hightensile strength and restricts the elongation. The leather embossinggrain can have the resemblance of the skin of a kid goat or sheep(skiver) and is applied using an embossing cylinder drum at a pressureof 60 tons at around 180 degrees Celsius (° C.). Because of the frontand backside coatings the fabric is not porous.

The material for the cover layer may be a cloth product, with chemistryin the coatings and a leather-like appearance to the cloth, such as byHolliston Inc. (905 Holliston Mills Road, Church Hill, Tenn. 37642;www.holliston.com)

The material for the inlay substrate may be Teslin™, a waterproofsynthetic film, single-layer, uncoated with a thickness of 356 microns.

Typically, the cover material is supplied in web form and coated with anadhesive with a short opening time, before laminating with an inlaylayer. Such web coating machines are supplied by Nordson(http://www.nordson.com) which operate on the principle of a slot nozzlesystem to apply the adhesive layer to the cover material.

A number of disadvantages are evident when processing cover material inweb form. Because of the nature of the fabric material and thesupplier's manufacturing process, they are many defects such asblemishes, scratches, cross directional lines, un-textured surface, bentedges and dents in the cover layer when supplied in web form. Thesorting of these defects is best done by the supplier of the coverlayer, but this limits the format of the deliverable cover layer tosheets.

However, in processing sheets, it is necessary to use a roller coaterinstead of a slot nozzle system which is generally used in processingweb material. The roller coater basically applies the adhesive to thecover material via a rotating roller.

A disadvantage of the roller coater is that an impression is left on theadhesive layer from the roller, leaving a rough surface texture. Thismay be particularly troublesome at the hinge area of an electronic coverinlay, having an uneven surface to attach the passport booklet to theinlay cover.

The production of an electronic passport cover (such as shown FIG. 1G)in may involve the adhesive attachment of an inlay substrate with acover layer.

FIG. 3H is a simplified cross-sectional view of a passport cover havinga cover laminated to an inlay substrate, and showing a hinge gap. Afront panel is on one side of the gap, a back panel is on the other sideof the gap. A chip module (CM) and antenna may be disposed in either oneof the front or back panels of the inlay substrate.

FIG. 3I is a plan view illustrating an “inlay”, (or “passport inlay”, or“e-cover inlay”) for preparing three (3) “passport covers” (such asshown in FIG. 1G). The cover layer 304 is shown partially, so as toreveal the underlying inlay substrate 302. FIG. 3J is a cross-sectionalview through FIG. 3I.

An e-cover inlay 300 having a “front” portion and a “back” portion, andmay comprise (compare FIG. 1H, but without a bottom layer):

-   -   a cover layer (cover material) 304, such as approximately 350 μm        thick; and    -   an inlay substrate 302, such as approximately 356 μm thick (14        mils) Teslin™

The material for the cover layer 304 may be PVC coated offset board oracrylic coated cotton, embossed and thermo-resistant. In the case of thefabric material, the backside coating can be water-base coated(aqueous/non-solvent), synthetic coated or have no coating. The frontside coating can have two base coatings and one top coating of acrylic.An alternative to acrylic coating is peroxylene-based coating(nitrocellulose). The fabric can have a strong bias (diagonal) in theweave (drill weave as opposed to linear weave) which gives it hightensile strength and restricts the elongation. The leather embossinggrain can have the resemblance of the skin of a kid goat or sheep(skiver) and is applied using an embossing cylinder drum at a pressureof 60 tons at around 180 degrees Celsius (° C.). Because of the frontand backside coatings the fabric is not porous.

The material for the cover layer 304 may be a cloth product, withchemistry in the coatings and a leather-like appearance to the cloth,such as by Holliston Inc. (905 Holliston Mills Road, Church Hill, Tenn.37642; www.holliston.com)

The material for the inlay substrate 302 may be Teslin™, a waterproofsynthetic film, single-layer, uncoated with a thickness of 356 microns.

The material for the inlay substrate 302 may be PVC, PC, PE, PET, PETE,TYVEK, TESLIN, Paper or Cotton/Noil. The inlay substrate can also havespecial markings such as luminous threads, water marks, microscopicfilings and optical polymer memory for additional security.

The inlay format is typically “3up” (for making three passport covers atonce), and is generally planar and rectangular, having exemplary overalldimensions of 404.81 mm×182.56 mm×0.70 mm (thick). Each one of the threecovers (A), (B) and (C) are generally rectangular, having exemplarydimensions of (404.81 mm/3)=134.94 mm×182.56 mm, with a thickness of0.70 mm. In FIG. 3I, “A”, “B” and “C”, each represent a “transpondersite” for a given passport cover (see FIG. 1G).

A hinge gap 316 may be cut or punched through the inlay substrate 302and the cover layer 304, separating the “front” portion from the “back”portion of the passport cover(s).

An RFID chip module 308 and corresponding antenna wire 310 may bedisposed in a recess 306 in the inlay substrate 302.

The inlay substrate 302 may be prepared by embedding an insulated wire(such as 80 μm) into the inlay substrate to form an antenna 110 with 4or 5 turns and interconnecting the ends of the antenna wire to the chipmodule by means of thermo-compression bonding.

The chip module 308 may be disposed in a recess 306 in the inlaysubstrate. The recess may be slightly wider than the chip module. Therecess may be a “stepped” recess, as shown, and may be a “window” recessextending completely through the inlay substrate 302.

The cover layer 304 may be laminated (joined) to the inlay substrate 302using a polyurethane hot melt adhesive 314, such as approximately 50-80μm thick. Prior to the adhesive process, the inlay substrate may bepre-pressed to ensure that the antenna wire does not protrude over(extend above) the surface of the Teslin™ substrate, in other words, toensure that the antenna wire is fully embedded in the inlay substrate.

Non-reactive adhesives based on polyamide are typically not used inelectronic passports for security reasons, as it would be possible tode-laminate the material by applying heat. Instead, reactive adhesive,moisture curing hot melt adhesive based on polyurethane, is used. Manyare available.

The adhesive can be characterized by a high initial tack and a long opentime (several minutes) or a short setting time (several seconds). In thelatter case, the adhesive has to be reactivated using infra red lightbefore the cover layer is attached to the inlay, or hot laminated withina certain period (within 1 to 2 hours). The adhesive cures exclusivelyin the presence of moisture and gains its final strength after 3 to 7days.

The adhesive may be applied to the cover layer (cover material) atapproximately 150 degrees Celsius, putting down a layer of 50 to 80microns (μm). The inlay is applied to the cover layer (cover material)in web or in sheet form, and is then laminated together using a rollpress. Thereafter, the laminated inlay with the cover layer (covermaterial) is cut to size and stored in a stack for 3 to 7 days in astorage area having a regulated temperature and humidity.

According to an embodiment of the invention, a transfer substrate suchas Teflon may be coated with an adhesive layer, then later reactivatingthe adhesive layer through the application of heat and transferring thesmooth side of the adhesive layer to the cover material. The process ofproviding a smooth adhesive finish on the cover material, especially inthe hinge area, may facilitate the adhesive attachment of the passportbooklet to the inlay cover. Portions of the process may be applicable toother process disclosed herein, and may be performed using the followingsteps.

Roller Coater Station: (FIG. 3K)

A conventional roller coater can be used to coat a transfer substrate,such as Teflon™, with an adhesive layer. The transfer substrate can be asheet, or it can be continuous band (much in the way of a conveyor beltwhich passes under the roller coater.) The transfer substrate should bea non-stick material, such as Teflon. A suitable thickness is 0.230 mm.

The adhesive (polyurethane reactive glue) is applied to the transfersubstrate with minimal pressure at a temperature of approximately 150°C.

The top surface (as shown) of the transfer substrate will thus beprovided with an adhesive layer. And, since the surface of the transferlayer is very smooth (substantially “smooth as glass”), the resultingadhesive layer will also be substantially smooth, and of substantiallyconstant thickness.

Cover Placement Station: (FIG. 3L)

After applying adhesive to the coated transfer substrate, a layer ofcover material may be placed onto the adhesive-coated transfersubstrate. The cover material may be in sheet form. In the figure, thetransfer substrate is adhesive-side up. A robot can place a sheet ofcover material “face down” onto the transfer substrate. The “inner”surface of the sheet of cover material is disposed against theadhesive-coated surface of the transfer substrate. The inner surface mayhave acrylic material on it.

Alternatively, the transfer substrate could be above the sheet of covermaterial (FIG. 3L, inverted).

Lamination Station: (FIG. 3M)

Then at a belt lamination station, the adhesive is reactivated andtransferred to the cover material by applying heat and pressure (arrows)to the “sandwich” of coated transfer substrate and cover material.

The pressure applied by the belt laminator to the sandwich may be 2.5Newtons. The reactivation temperature is approximately 160° C. Theadhesive solidifies, non sticky, after the opening time of severalseconds.

The Cover Placement Station and Lamination Station may be combined withone another.

Finishing Station: (FIG. 3N)

In a final step, the cover material (now with adhesive on it) is removedfrom the transfer substrate, with the adhesive layer being transferredto the inner surface of the cover material. Next, the cover material (orlayer, or simply “cover”) may be laminated to an inlay substrate havinga chip module and antenna wire.

Laminating the Cover to the Inlay Substrate

In preparing the cover material for adhesive attachment to the inlayusing polyurethane reactive glue, the following steps may be performedto augment the adhesion and shear strength:

-   -   since the textile of the cover material may be coated with an        acrylic, it may be beneficial to first (before laminating)        partially remove acrylic around the area of the chip module and        antenna by ablating the material using a UV laser, and secondly        to reduce the surface tension of the material by applying        (increasing) temperature before coating. The latter procedure        prevents curling of the material after lamination with the inlay        layer such as Teslin™.

The use of a transfer substrate or carrier layer for the purpose offorming an antenna structure and mounting the antenna structure to aninlay substrate is described below.

Forming Antenna Structures on an Antenna Substrate and Transferring themto the Inlay Substrate

Generally, a plurality of antenna structures (or simply “antennas”) maybe formed (produced) a plurality of antenna sites on an “antennasubstrate” which is other than (separate from) the inlay substrate, suchas by using the ultrasonic embedding techniques described hereinabove(for example, U.S. Pat. No. 6,233,818).

Some of the techniques described hereinabove for forming an antenna(antenna structure) on an inlay substrate may be applicable to formingantenna structures on the antenna substrate. For example

-   -   The antenna structures may be formed on the antenna substrate        using any of the techniques described hereinabove, including        (but not limited to) ultrasonically scribing an antenna wire        onto the substrate, first forming channels for accepting the        antenna wire and laying the antenna wire into the channels        (FIGS. 2G,H), and first forming a wide trench (FIG. 3F) in the        substrate for accepting at least two turns of an antenna wire.    -   The antenna structure may comprise self-bonding wire. The        antenna structure may comprise an etched conductive film. The        antenna structure may comprise channels formed in the antenna        substrate which are subsequently filled with a conductive        material (compare FIGS. 2I,J). The antenna structure may        comprise channels formed in an adhesive layer on the antenna        substrate which are subsequently filled with a conductive        material (compare FIGS. 2K,L).

A transponder site may comprise a selected area of an overall inlaysubstrate (such as Teslin™ or PC) and an RFID chip module (or die, orchip) which may be mounted in a recess.

The antennas (antennae) may be transferred from the antenna substrate totransponder site(s) on an inlay substrate, and connected with the chipmodule(s) at the transponder sites. Alternatively, a chip module may bemounted to the antenna on the antenna substrate, and the combination(s)of antenna and chip module may be transferred to the transpondersite(s).

Various cover layers and underlay layers may be applied to the inlaysubstrate with antenna and chip module in place, and the severaltransponder sites may be separated from one another, becoming individualsecure documents such as electronic passports or ID cards.

The separate substrate upon which the antenna structures are formed maybe referred to as a “carrier substrate”, or a “transfer substrate”, andmay comprise a layer or a film of material, In its various forms theseparate substrate upon which the antenna structures are formed maysimply be referred to as an “antenna substrate”. The antenna substratemay be a single layer (monolayer) substrate or a multi-layer substrate.

In some embodiments, the antenna substrate may be in the form of anelongate continuous web (or strip) of synthetic material upon which theplurality of antenna structures may be formed, one after the other, in alinear sequence (or one row of “n” antenna structures). The antennasubstrate in such a “web format” may for example be approximately oneantenna structure wide (such as several centimeters wide), and several(n) antenna structures long (such as several meters long). In such a webformat, the pattern and layout of the several (n) antenna structures onthe antenna substrate may be independent of a pattern and layout of aplurality of corresponding transponder sites on the inlay substrate.

In some embodiments, a 2-dimensional array (such as “n” rows and “m”columns) of antenna structures may be formed on the antenna substrate,such as for transfer “en masse” (all at once) to the plurality ofcorresponding transponder sites on an inlay substrate. In this case, thepattern and layout of the (n×m) antenna structures on the antennasubstrate may correspond to a pattern and layout of correspondingtransponder sites on the inlay substrate.

In some embodiments set forth herein, a single antenna structure at asingle antenna site on the antenna substrate may be described, asexemplary of other of the several antenna structures at other antennasites on the antenna substrate.

The antenna substrate may be formed of a synthetic material, such as PVCor PC. The material of the antenna substrate may be the same as, ordifferent than the material of the inlay substrate. The antennasubstrate may be formed of non-synthetic material, such as aluminum orpaper. The antenna substrate may be a multi-layer substrate, comprisinga layer or film of material on an underlying carrier layer. For example,the antenna substrate may comprise a layer of adhesive on an underlyingcarrier substrate or web (such as Teflon™), and the antenna structuresmay be formed in the layer of adhesive.

Each of the antenna structures may comprise a flat (generally planar)coil having a number (such as four or five) turns of an elongateelectrical conductor (such as a wire, a foil, conductive material,conductive material disposed in a channel, and the like), generallyhaving two “termination ends” (or “terminal ends”). The termination endsmay be the two ends, end segments, end portions, or any suitable“connection portions” of the antenna structure. Refer to FIG. 1E.

The antenna structure(s) may be mounted to either (upper or lower)surface of the antenna substrate (although normally formation of theantenna structures would proceed on the upper/top surface of the antennasubstrate), and the antenna substrate may be inverted for transferringthe antenna structure(s) to the inlay substrate. During the process oftransferring an antenna structures, the inlay substrate would normallybe disposed under the antenna substrate (or relevant portion thereof).

An inlay substrate may be prepared with a plurality of RFID chips or(chip modules) located at a plurality of transponder sites in an inlaysubstrate. For example, a 2-dimensional array (“n” rows, “m” columns) of“transponder sites” on a single inlay substrate. The inlay substrate maybe a single layer substrate or a multi-layer substrate, and may beformed of Teslin™, PC, other synthetic material or paper.

At each transponder site, the RFID chip (or chip module) may be disposedin a recess (compare FIGS. 2A,B) extending into a surface of the inlaysubstrate. The recess for the RFID chip (or chip module) may be formedin the inlay substrate by laser ablation. In some embodiments set forthherein, one transponder site may be described, as exemplary of other ofthe plurality of transponder sites on the inlay substrate.

Channels (compare FIG. 2C), or more likely wide trenches (compare FIG.3F) may be prepared in the inlay substrate for receiving the antennastructures (when they are transferred from the antenna substrate to theinlay substrate), and these channels or wide trenches may extend to andfrom edges of recesses (compare FIGS. 2F, 3G) in which the RFID chips(or chip modules) are disposed, or even at least partially into therecess. The channels or wide trenches may be formed in the inlaysubstrate by laser ablation.

A wide trench to accept an antenna structure may be partially filledwith adhesive. Alternatively, a layer of adhesive could be disposed overthe entire area of the inlay substrate covering the trench for theantenna structure and the recess for the chip module. In placing thechip or chip module in its laser ablated recess, the adhesive would actas an anti-fretting medium to reduce the risk of micro-crackingespecially in polycarbonate cards.

Generally, a plurality of antenna structures may prepared in advance onthe antenna substrate, and transferred on an “as needed” basis selectedtransponder sites on the inlay substrate, and connected to the RFID chip(or chip module) at the transponder sites.

In some embodiments, the antenna structures may be transferredone-by-one (individually) to selected ones of the transponder sites,which may comprise “singulating” or separating the antenna structuresindividually from the antenna substrate. In some embodiments, more thanone antenna structure may be transferred at once (“en masse”) tocorresponding more than one transponder sites on the inlay substrate.

For transferring antenna structures from the antenna substrate toselected transponder sites on the inlay substrate, there are a varietyof possibilities, including but not limited to:

-   -   a pick & place machine may be used to remove (pick) individual        antenna structures from the antenna substrate and transfer        (place) them to selected transponder sites on the inlay        substrate,    -   a portion of the antenna substrate surrounding (encompassing,        supporting) the given antenna structure may be disposed facing a        selected transponder site, and mechanical means such as pins may        act upon the antenna substrate (such as applying a force to the        back side of the antenna substrate) cause the antenna        structure(s) to be released (ejected) from the antenna substrate        and mounted to (disposed onto) the inlay substrate,        -   the inlay substrate may be prepared with channels for            receiving corresponding turns (such as wires) the antenna            structure    -   a portion of the antenna substrate surrounding (encompassing,        supporting, carrying) the given antenna structure may be        perforated, and in the process of transferring the antenna        structure to the inlay substrate, some “residual” antenna        substrate material may accompany the antenna structure        -   the inlay substrate may be prepared with wide trenches for            receiving the antenna structure with residual antenna            substrate material    -   a laminating process (generally, heat and pressure) may be used        to transfer antenna structures from the antenna substrate to        transponder sites on the inlay substrate.

Because the antenna is first arranged on or in (adhered to or at leastpartially embedded in) the carrier layer (film), the pitch (distancebetween the antenna wires or conductor tracks) and the shape of theantenna remain intact during the transfer and mounting of the antennastructure and its termination ends. The fixing of the antenna onto orinto the inlay substrate may be through the application of heat andpressure.

In the “modified coil winding” technique disclosed in US 2008/0314990(Rietzler), there is a one-to-one correspondence between the number andformat (layout, pattern) of antenna devices (22) on the sheet (13) andchip modules (21) on the laminator plate (17). Similarly, in U.S. Pat.No. 7,229,022 (Rietzler) there is a one-to-one correspondence betweenthe number and format (layout) of antennas (12) on the substrate (11)and the chip modules (15) on the second substrate (14). Thiscorrespondence requires a high level of registration.

In the Rietzler techniques, generally, the antennas are formed on whatis the inlay substrate, not on a separate antenna substrate which isultimately removed. There is no transfer of antenna structure involved.)The one-to-one correspondence of antennas to transponder sites is due tothe fact that the antennas are indeed formed at the transponder sites,and the chip modules are added thereto. (Compare U.S. Pat. No. 6,233,818which suggests installing chip modules from the bottom of the inlaysubstrate into recesses bridged by the antenna wire.)

In some embodiments of the techniques disclosed herein for formingantenna structures on an antenna substrate which is separate from theinlay substrate, then individually transferring the “pre-formed” antennastructures to transponder sites on inlay substrate, there need not be acorrespondence between the number and/or layout of antenna structures onthe antenna substrate and the number and/or layout of transponder siteson the inlay substrate. For populating the total number of transpondersites of a given inlay substrate, there should of course be at least asufficient number of antenna structures available on the antennasubstrate, but their layout (arrangement or positioning on the antennasubstrate with respect to one another) is essentially entirelyindependent of the layout (arrangement or positioning) of thetransponder sites on the inlay substrate.

In some embodiments of the techniques disclosed herein for formingantenna structures on an antenna substrate which is separate from theinlay substrate, then transferring the “pre-formed” antenna structuresen masse (several at once) to transponder sites on inlay substrate,there generally would be a correspondence between the number and/orlayout of antenna structures on the antenna substrate and the numberand/or layout of transponder sites on the inlay substrate.

In some embodiments of the techniques disclosed herein for transferringthe “pre-formed” antenna structures from the antenna substrate to theinlay substrate, whether one-by-one or en masse, during the transferprocess the termination ends of the antenna structure are fixed relativeto each other on the antenna substrate and cannot be misaligned duringplacement (transfer).

In some embodiments of the techniques disclosed herein for transferringthe “pre-formed” antenna structures from the antenna substrate to theinlay substrate, whether one-by-one or en masse, after the transferprocess the antenna substrate is substantially removed (a small portionof the antenna substrate may remain in some embodiments) or taken away,no longer being associated with the antenna structure(s) which has(have) been transferred. The antenna substrate may or may not be reusedfor forming subsequent antenna structures.

An Illustration of the Process

FIG. 4 illustrates a representative antenna structure 420 disposed on aninlay substrate 402 at a selected transponder site 400. There may be aplurality of such transponder sites on the inlay substrate 402. Thedashed lines indicate that there may be additional transponder sitesabove, below, to the left of and/or to the right of the illustratedtransponder site 400. For example, there may be 2 rows (extending oneatop the other, across the page), each row having four transpondersites. For example, there may be three rows, each row having threetransponder sites. Generally, all of the transponder sites will besubstantially identical with one another, and eventually will beseparated from the remaining transponder sites in the inlay substrate inthe process of making secure documents such as electronic passports orID cards. One transponder site may be described in detail, asrepresentative of other transponder sites on the inlay substrate.

A chip module 408 may be disposed in a recess 406 in a surface of theinlay substrate 402, and may have two terminals (or terminal areas) 408a and 408 b. The antenna structure 420 may be formed of several (such asfour or five, although only two are shown) turns of wire 410. Theantenna wire may have two termination ends (or connection portions) 410a and 410 b. The two termination ends 410 a and 410 b may be disposedover respective terminals (terminal areas) 408 a and 408 b of the chipmodule 408 for connection thereto, and may be physically and/orelectrically connected (typically bonded) thereto using conventionalmeans. A transponder site having a chip module and an antenna connectedthereto may be referred to as a “transponder”. Compare FIGS. 1A and 1B.

The inlay substrate 402 may be prepared with a wide antenna trench(laser ablated or mechanically milled) to accept the antenna structureand a recess (also laser ablated or mechanically milled) or window toaccept the chip or chip module. The trench may be a wide trench.

The interconnection of the termination ends of the antenna structure 420may be connected to a chip (or chip module) residing in the inlaysubstrate (laser ablated recess or cavity), in a window in the inlaysubstrate supported by an underlying layer of material or on the inlaysubstrate.

The inlay substrate 402 may comprise a synthetic material such asTeslin™ having a thickness of approximately 356 μm, or polycarbonate(PC) having a thickness of approximately 185 μm, and may be in a sheetformat. The antenna wire 410 (generally exclusive of the connectionportions) may be mounted to the inlay substrate 402 using conventionalmeans, such as by scribing, sticking or embedding. Compare U.S. Pat. No.6,233,818. The antenna wire 410 (generally exclusive of the connectionportions) may be disposed in channels which are preformed in the surfaceof the inlay substrate, such as by laser ablation. Compare FIG. 2C. Therecess may be formed by in the inlay substrate by laser ablation.Compare FIGS. 2A,B

FIG. 4A illustrates a plurality of antenna structures (or simply“antennas”) 420A which have been formed on an antenna substrate (carrieror transfer substrate, or web, or film or layer) 412A at a plurality ofantenna sites 414A on the antenna substrate 412A. The antenna structure420 may comprise antenna wire 410 which may be mounted to (including atleast partially embedded in) the substrate using self-bonding wire, in aconventional manner (compare FIG. 1B), such as having a main portioncomprising four or five turns of wire. Termination portions (connectionportions) 410 a and 410 b of the antenna wire 410 (hence, of the antennastructure 420) extend from the main portion and are positioned so thatthey will be aligned with corresponding terminal areas (408 a and 408 b)on chip modules (408) at transponder sites (400B) on an inlay substrate(402B).

The dashed lines on the antenna substrate 412A indicate that there maybe additional antenna sites 414A above, below, to the left of and/or tothe right of the illustrated antenna site. In FIG. 4A, a single row of(two) antenna sites 414A is illustrated. The antenna substrate 412A maybe in the form of an elongate web having a long row of several antennastructures 420A.

The antenna substrate (or carrier layer, or web, or film) 412A maycomprise a paper or a synthetic material, such as an overlay materialhaving a thickness between 30 and 80 microns and can be identical to thematerial used for the inlay substrate (such as PVC or PC) which formsthe inner layer of a contactless smart card or national identity card.In the case of an electronic passport having a monolayer substrate (suchas Teslin™) as the inlay substrate, the carrier layer may be a layer ofpolycarbonate or a layer of adhesive such as polyurethane. Compare FIGS.2G and 2H. The antenna substrate (carrier layer) may be in the form ofan endless web or reel (spliced as required) carrying (supporting, uponwhich may be formed) a plurality of antenna structures.

The antenna structures 420A may be formed in any of the mannersdescribed hereinabove with regard to mounting antenna wire on an inlaysubstrate, such as by ultrasonic sticking of wire to the antennasubstrate 412A.

The antenna can be arranged on or in the antenna substrate (carrierlayer, carrier film) by scribing a wire conductor onto or into thematerial, such as by means of ultrasonic embedding. An 80-112 μmdiameter wire may be embedded partially in a carrier film having athickness of 50-80 μm. The wire conductor can be an insulated wire or aself-bonding wire.

As an alternative to wire, the antenna could be formed from a sheet ofmetal such as a copper foil with a layer of passivation to preventoxidization, and the shape and tracks of the antenna could be realizedby cutting the copper using a UV picosecond laser.

The antenna substrate (carrier layer, carrier film) may be provided withchannels for accepting a wire conductor, electronic ink, conductivepaste, electrically charged nano-particles or any conductive medium. Alaser may be used to activate the medium for electrical conduction.

The removal (singulation) of the antenna structure and its terminationends from the antenna substrate (carrier layer, carrier film) may beperformed using a die punch, a laser for cutting or by means oflamination (heat and pressure), before transferring and mounting onto orinto an inlay substrate. A contact transfer process (which may be a formof lamination) is also described.

The exposed antenna could be adhesively attached to the antennasubstrate (carrier layer, carrier film) before or after the laserablation/cutting process. The antenna may also be formed and mounted tothe antenna substrate (carrier layer, carrier film) through theconventional method of coil winding (radial or flyer principle).

FIG. 4B illustrates an inlay substrate 402B comprising a plurality oftransponder sites 400B which are prepared on the inlay substrate. Thedashed lines indicate that there may be additional transponder sitesabove, below, to the left of and/or to the right of the illustratedtransponder site. A single row of transponder sites 400B is illustrated.The inlay substrate 402B may comprise a synthetic material such asTeslin™ or polycarbonate (PC), having respectively a thickness of 356 μmand 185 μm, and may be in a sheet format. At each transponder site 400B,a chip module 408 may be disposed in a recess 406 in a surface of theinlay substrate 402B. The chip module 408 may have two terminals 408 aand 408 b.

Alternatively, the chip module may be mounted to the antenna on theantenna substrate prior to transfer, and the combination(s) of antennaand chip module may be transferred together to the transponder site(s).In such as case, the “transponder site” would essentially consist of anarea of the inlay substrate designated for receiving a chip module andantenna, without the chip module installed in the recess. Thisdesignated area may be distinguished by (i) a recess in the inlaysubstrate for receiving the chip module, (ii) an area of the inlaysubstrate adjacent the recess for receiving the turns of the antennastructure, and (iii) a remaining area around the chip module and antenna(after installed) for defining a suitable overall size for the securedocument.

FIG. 4C illustrates such an arrangement. A chip module 408 is connectedby its terminal areas 408 a and 408 b to terminal ends 410 a and 410 bof an antenna structure 420 which has been formed at an antenna site414C on an antenna substrate 412C. The antenna substrate 412C is abovean inlay substrate 402C for transferring (by any of the techniquesdescribed herein) the antenna structure with chip module to atransponder site 400C on an inlay substrate 402C having a recess 406Cfor receiving the chip module. At the back of the recess 406C, twochannels 426 are visible for receiving the terminal ends 410 a and 410 bof an antenna structure 420 may be seen, and a wide trench 428 forreceiving the main body (turns) of the antenna structure 420 can also beseen. The antenna structure 420 may be wire which is embedded onto orinto the antenna substrate 412C. Channels 424 (shown exaggerated insize, for illustrative clarity) may be provided in the antenna substrate414C for receiving the antenna wire.

Various techniques are described hereinbelow for transferring antennastructures 420A individually (one-by-one) or several at a time (enmasse) from the antenna substrate 412A to one or more transponder sites400B on the inlay substrate 402B.

A resulting product (or interim product) may look substantially like thetransponder shown in FIG. 4, with an antenna structure 420 a connectedto the chip module 408. Cover layers and/or overlay (or underlay) layersmay be provided in a final product, such as a secure document which maybe an electronic passport or ID card. Refer to FIGS. 1F and 1H.

Security features such as markings may be incorporated into the antennasubstrate (carrier layer) 412A, such as graphic designs in an areaaround or underneath the antenna structure. This would create a visible“security feature”.

A hologram may be created using the laser on the underside of the inlaysubstrate 402B, such as opposite the chip module. This would create avisible “security feature”.

Some inlay substrates comprise polycarbonate (PC), and tend to developmicro cracks in the area of the chip module (around the recess). Toreduce the formation of (prevent) micro cracks developing inpolycarbonate (PC), at the position of the chip module (around the edgeof the recess), the material of the inlay substrate can be lasertreated, a form of annealing it at the threshold fluence (just belowablating, with incubation effect).

Some Embodiments

FIG. 5A shows a representative antenna structure 520 (compare 420A)having a representative termination end 510 a (compare 410 a, 410 b)which has been formed on a representative antenna site 514 (compare414A) on an antenna substrate 512 (compare 412A). A representativetransponder site 500 (compare 400B) on an inlay substrate 502 (compare402B) comprises a chip module 508 (compare 408) disposed in a recess andhaving a representative terminal 508 a (compare 408 a, 408 b).

A tool such as a conventional “pick & place” gantry (such as aconventional surface mount technology pick and place machine) may beused to remove (pick) individual antenna structures 520 off of theantenna substrate 512 and transfer them, one-by-one, in an alignedmanner, to selected transponder sites 500 on the inlay substrate 502.The pick & place gantry may position (place) the antenna structure 520with its termination end 510 a located over a respective terminal 508 a(compare 408 a and 408 b) of the chip module 508 for connection theretousing conventional means (such as thermocompression bonding). Theantenna structure 520 (and termination end 510 a) is shown in dashedlines on the antenna substrate 512 from whence it was picked, and insolid lines on the inlay substrate 502 whereat it is placed.)

The technique of FIG. 5A illustrates that the layout of antennastructures on the antenna substrate may be completely independent of thelayout of transponder sites (and position of chip modules within thetransponder sites) on the inlay substrate. In this embodiment, theposition (or location) of the antenna substrate, and its orientation(“face up”, as shown) is substantially arbitrary with respect to theposition of the inlay substrate (other than both the antenna substrateand inlay substrate being within “reach” of the pick & place gantry).

FIG. 5B shows a representative antenna structure 520 having arepresentative termination end 510 a which has been formed on arepresentative antenna site 514 on an antenna substrate 512. Arepresentative transponder site 500 on an inlay substrate 502 comprisesa chip module 508 disposed in a recess and having a representativeterminal 508 a.

In this embodiment, the antenna substrate 512 is oriented “face down”,with the antenna structure 520 aligned over and spaced only slightlyapart from the transponder site 500 on the inlay substrate 502. The gapbetween the antenna substrate 512 and the inlay substrate 502 is greatlyexaggerated in this “exploded” view. A pick and place tool can also beused to transport the antenna substrate or portion thereof, and theantenna substrate transporting an antenna structure may be held inposition using vacuum through micro-holes in the pick & place tool.

Mechanical means 530 may be employed for releasing (separating,ejecting) the antenna structure 520 from the antenna substrate 512, inan aligned manner onto the transponder site 500, with the terminationend 510 a on the terminal 508 a for subsequent bonding thereto. Themechanical means 530 may comprise a pin or pins pressing on the backside (top, as viewed) of the antenna substrate 512. The pins may extendthrough holes in the antenna substrate 512 to act directly on theantenna structure 520. The mechanical means 530 may cause flexing (orbowing) of the antenna substrate 512 so that the antenna structure 520disassociates itself therefrom (“pops off”) as a result of thedeformation of the antenna substrate 512. The antenna structure 520 (andtermination end 510 a) is shown in dashed lines on the antenna substrate512, and in solid lines on the inlay substrate 502. If the chip moduleis first mounted and connected to the antenna structure (prior to makingthe transfer), this may help maintain alignment of the termination endsof the antenna structure, and may also facilitate separation of theantenna structure from the antenna substrate.

Alternatively, the means for releasing the antenna structure 520 fromthe antenna substrate 512 may be a laser (beam) directed at the backside of the antenna substrate 512 tracing a path corresponding to the“footprint” or outline of the antenna structure (on the front side ofthe antenna substrate 512) to cause (or assist) in releasing the antennastructure 520 from the antenna substrate 512 onto the inlay substrate502. The fluence of the laser should be sufficient to heat a portion ofthe antenna substrate 512, causing softening or distorting, withoutpenetrating the antenna substrate 512.

In this embodiment, the antenna structure 520 may have been formed onthe antenna substrate 512 with the antenna substrate “face up”, and theantenna substrate 512 is inverted prior to its being positioned over theinlay substrate 502 for transferring the antenna structure 520 from theantenna substrate 512 to the inlay substrate 502.

FIGS. 5C,5D,5E illustrate an embodiment wherein the antenna substrate512 is perforated, and at least a portion 512 a of the antenna substrate512 supporting the turns of the antenna structure 520 (exclusive of thetermination ends 510 a, 510 b) may remain with the antenna structure 520when it is transferred from the antenna substrate 512 to the inlaysubstrate 502.

More particularly, a row (or ring) of perforations 522 is disposedinterior (adjacent, inside of) the turns of the antenna structure 520,and a row (or ring) of perforations 524 is disposed exterior (adjacent,outside of) the antenna structure. The perforations may be formed bylaser ablation of the substrate material, in a manner similar to formingrecesses (compare FIGS. 2A,2B), channels (compare FIGS. 2C, 2D, 2E, 3E)or wide trenches (compare FIG. 3F).

In FIG. 5C, the antenna substrate 512 is illustrated herein as a carrierfilm (web). The portion 512 a of the antenna substrate 512 remainingwith the antenna structure 520 comprises a ring of antenna substratematerial under the antenna structure 520 between the inner and outerrows of perforations 522 and 524. (The angles at which the terminationends extend from the main body portion of the antenna structure areshown differently in FIG. 5C than in FIG. 4A to suggest that variousantenna configurations are possible.)

Additional perforations (not shown) may be provided in the antennasubstrate 512 so that a portion of antenna substrate material (orcarrier layer or web) may remain with the antenna structure 520,supporting the termination ends 510 a and 510 b, when the antennastructure 520 is transferred from the antenna substrate 512 onto theinlay substrate 502. Alternatively, by first mounting and connecting thechip module to the antenna structure (prior to the transfer), thetermination ends will stay aligned. Where antenna substrate materialaccompanies the antenna structure during transfer, particularlysupporting the termination ends of the antenna wire, openings may beformed in the antenna substrate at the location of connection portionsof the termination ends so as to facilitate bonding of the connectionportions to the terminals of the chip module.

FIG. 5D illustrates a relevant portion of the antenna structure 520(comprising four turns of wire) prior to the antenna structure 520 beingseparated from the antenna substrate 512. As indicated by this figure,the antenna structure 520 may be formed on the antenna substrate 512with the antenna substrate “face up”.

FIG. 5E illustrates a relevant portion of the now “singulated”(separated from the antenna substrate 512) antenna structure 520(comprising four turns of wire) prior to the antenna structure 520 afterbeing separated from the antenna substrate 512. As indicated by thisfigure, the antenna structure 520 with remaining portion 512 a of theantenna substrate 512 may first be inverted (“face down”) prior totransferring the antenna structure to the inlay substrate. As shown inthis figure, the antenna structure 520 (with remaining portion 512 a ofthe antenna substrate 512) may be disposed in a wide trench 504 formedin the inlay substrate 502. Compare FIG. 3F (322).

Before further processing of the carrier layer in transferring theantenna structure to an inlay substrate, the carrier layer with thearranged antenna(e) may be laminated to create a smooth surface,“sealing” around the antenna. This may result, for example, in some (athin film) of the antenna substrate material sticking to and stayingwith the antenna structure, which may result in greater stability of theantenna structure during the transfer process.

These FIGS. (5C, 5D, 5E) illustrate that a portion of the antennasubstrate (carrier web) may be removed, with a given antenna structuremounted thereto, and positioned it so that the antenna structure 520 isaligned directly over a given transponder site (500), then causingseparation of the portion of the carrier web with the antenna structure,directly over the transponder site. The antenna substrate 512 may have asufficient number of antenna structures 520 to populate an entire arrayof transponder sites (such as three, or six, or nine, or more) on aninlay substrate sheet.

The process of transferring the antenna structure(s) to the transpondersite(s) may be performed by first contacting the relevant portion of theantenna substrate (carrier web) with the transponder site, the antennastructure (with or without remaining carrier web) “sticks” (adheres) tothe transponder site, then removing (taking away) the antenna substrate.This phenomenon may be aided by using a different (dissimilar) materialfor the antenna substrate than for the inlay substrate, and may also beencouraged by performing a laminating process. For example, using a bandlaminator (such as http://www.meyer-machines.com/engl/), or a rollcoater, antenna structures formed in a PVC antenna substrate maytransfer readily to an inlay substrate comprising Teslin™. A coated,insulated or self-bonding wire may be used for the antenna structure,and surface tension, or simple adhesion may be the principle at work in“attracting” the antenna wire to the dissimilar material of the inlaysubstrate. Channels or a wide trench may be formed in the inlaysubstrate prior to the transfer, the structure of which may also aid inthe transfer process. Compare the profiled channel shown in FIG. 2E.

FIG. 6A shows a portion of a representative antenna structure 620 whichhas been formed on a representative antenna site 614 on an antennasubstrate 612. The termination ends of the antenna structure areomitted, for illustrative clarity. Compare FIGS. 4, 4A, 5B, 5D. Theantenna substrate 612 may comprise PVC.

FIG. 6B shows the antenna substrate 612 inverted (“face down”) anddisposed on a representative transponder site 600 on an inlay substrate602. The inlay substrate 602 may comprise Teslin™. The chip module(having terminals) which may be disposed at the transponder site (andwhich may be disposed in a recess in the inlay substrate) is omitted,for illustrative clarity. Compare FIGS. 4, 4B, 5B

The antenna substrate 612 and inlay substrate 602 are put in (orthrough) a laminator, such as a band laminator, having a upper roller(or band) 632 and a lower roller (or band) 634. Compare FIGS. 3A, 3K.Some exemplary parameters for effecting the transfer of an antenna froma PVC sheet to a Teslin sheet may include: applying pressure and/or heatmay, such as 25 n/m² at 75-80° C., feeding both sheets (substrates)though the band laminator at a speed of 2 m/sec. This may be done withno cooling.

FIG. 6C shows that after laminating, the antenna substrate 612 may beremoved, leaving the antenna structure 620 mounted to the inlaysubstrate 602.

Restated more generally, the antenna substrate 612 which is “face down”and the inlay substrate 602 which is “face up” are brought intoface-to-face aligned contact with one another and subjected to aphysical process, such as a laminating process, which may involve atleast one of pressure, heat or time in an amount which is sufficient tocause the antenna structure 620 to transfer from the antenna substrate612 to the inlay substrate 602. This process may be referred to as a“contact transfer” process.

The termination ends of the antenna structure may be physically disposedon the terminal areas of the chip module after laminating (or after anyof the other transfer techniques disclosed herein, or theirequivalents). It is also possible that an electrical connection betweenthe termination ends of the antenna structure and the terminal areas ofthe chip module may be effected during the transfer process (laminatingor otherwise), without requiring a separate subsequent bonding process(such as thermocompression bonding). For example, a conductive adhesivemay be disposed on the terminal areas of the chip module prior totransferring the antenna structure, resulting in an electricalconnection between the terminal ends of the antenna structure and theterminal areas of the chip or chip module.

The physical process referred to in the contact transfer process may notinvolve laminating, but rather simply causing the antenna substrate andinlay substrate to be at different temperatures (causing a temperaturedifferential) and bringing them in contact with one another. Forexample, the antenna substrate may be in web form, supported by a heatedroller or conveyor, and the inlay substrate may be at room temperature(cooler than the antenna substrate), or cooled, in which case the“physical process” would simply be causing there to be a temperaturedifferential between the antenna substrate and the inlay substrate. Aphysical process such as causing there to be an airflow (or flow ofinert gas) between the opposing surfaces of the antenna substrate andthe inlay substrate may also assist in transferring the antennastructure(s) from the antenna substrate to the inlay substrate.

Physical characteristics (or properties) of the antenna wire and/orantenna substrate and/or inlay substrate may be selected to facilitatethe transfer of antenna structure from the antenna substrate to theinlay substrate. For example, the antenna substrate may be selected tohave a lower glass transition temperature than the inlay substrate. (seehttp://plastics.inwiki.org/Glass_transition_temperature) Surface tensionmay also be a factor. Gravity may have an effect since the inlaysubstrate may be disposed under the antenna substrate during thetransfer.

Phrased differently, at least one antenna site 614 of an antennasubstrate 612 which has been prepared with an antenna structure 620 (andoptionally also with a chip module connected to termination ends of theantenna structure) may be contacted with at least one transponder site600 on an inlay substrate 602 (which may have been prepared with a chipmodule), thereby transferring the antenna structure 620 from the atleast one antenna site 614 of the antenna substrate 612 to the at leastone transponder site 600 on the inlay substrate 602.

The inlay substrate 612 may then be removed, leaving the antennastructure 620 positioned with its termination ends (compare FIG. 4,elements 410 a, 410 b) on the terminal areas (compare FIG. 4, elements408 a, 408 b) of the chip module for connection (such as by thermocompression bonding, or gluing, or other process) thereto. Cover layersand the like may be applied to the resulting transponder site 600 withchip module and with antenna, thereby forming a secure document such asan electronic passport or ID card.

The antenna structures 620 may be formed (fabricated) in a “web format”,or a single row of several antenna structures (compare FIG. 5C), whereinthe antenna structures 620 may be transferred individually to selectedones of a plurality of transponder sites on an inlay substrate. Anentire array of transponder sites may be populated one-by-one withantenna structures in this manner.

The contact transfer process described herein may also be performed inan “array format” (compare FIGS. 4A, 4B), wherein a plurality of antennastructures may be formed with a given layout (such as an n×m array) ofantenna sites on an antenna substrate and transferred all at once (enmasse) to a similar plurality of transponder sites on an inlay substratehaving a similar layout (such as an n×m array).

FIG. 6D shows a plurality of antenna structures 670 (compare 420, 520,620) formed on a 2×2 array of antenna sites 664 (compare 414A, 514, 614)on an antenna substrate 662 (compare 412A, 512, 612). Each antennastructure 670 is shown having only one turn of wire (compare 410), forillustrative clarity. Each antenna structure 620 has two terminationends 660 a, 660 b (compare 410 a/b, 510 a/b). The antenna substrate 662may comprise a layer of PVC having a thickness of 200 μm.

FIG. 6E shows a plurality of chip modules 658 (compare 408, 508) formedon a 2×2 array of transponder sites 650 (compare 400B, 500, 600) on aninlay substrate 652 (compare 402B, 502, 602). Each chip module 658 hastwo terminal areas 658 a, 658 b (compare 408 a/b, 508 a Recesses in theinlay substrate are omitted, for illustrative clarity. The inlaysubstrate 652 may comprise a layer of Teslin™ having a thickness of 356μm. The dashed line at each transponder site 614 indicates(schematically) where the antenna structure 670 will be disposed (aftertransfer), and may be a wide trench 672 (compare 322) formed in theinlay substrate 652 for receiving the antenna structure 670.

FIG. 6F shows the antenna substrate 662 being brought into face-to-facecontact, or into near (almost) face-to-face contact with the inlaysubstrate, for effecting the transfer of at least one (two illustrated)antenna structures 670 from the antenna substrate 662 to the inlaysubstrate 652. This figure is an exploded view. Means for laminating,which may include means for effecting any of the physical processesdescribed hereinabove (pressure, temperature, temperature differential,air flow, etc.) may be used to cause or to assist the antenna structures670 being transferred from the from the antenna substrate 662 to theinlay substrate 652, in an aligned manner, for subsequent connecting ofthe termination ends (only one end 660 a is visible in thecross-section) of the antenna structures 670 to the terminal areas (onlyone terminal area 658 a is visible in the cross-section) of the chipmodules 658.

Some Conclusions, Benefits and Additional Features

Using the techniques disclosed herein may result in the alignedplacement of one or more antenna structures on one or more transpondersites for connecting (such as by bonding) termination ends of theantenna structure(s) to corresponding terminal areas of an RFID chip orchip module at the transponder site.

In the process, insulation may be removed from insulated antenna wire atthe termination ends (connection portions) of the antenna wire.

An entire antenna structure (typically comprising four or five turns ofantenna wire) may be disposed in a wide antenna trench prepared in theinlay substrate. (compare FIG. 3F)

Generally, using the techniques disclosed herein, different formatinlays (different arrangements of transponder sites on an inlay sheet)are readily accommodated, requiring only a simple programmingchange—where to place the antenna structure on the inlay substrate(transponder site)—the position of the target transponder site isprogrammable, requiring no mechanically adjustments for different inlayformats.

The material of the antenna substrate (carrier substrate) upon which theantenna structures are formed (“pre-fabricated”) may be the same ordifferent than the material of the inlay substrate upon which theantenna structure is transferred (mounted) for connection to an RFIDchip or chip module.

While the invention has been described with respect to a limited numberof embodiments, these should not be construed as limitations on thescope of the invention, but rather as examples of some of theembodiments. Those skilled in the art may envision other possiblevariations, modifications, and implementations that are also within thescope of the invention, based on the disclosure(s) set forth herein.

What is claimed is:
 1. A method of making a transponder comprising aninlay substrate, an RFID chip and an antenna structure, characterizedby: forming a wide trench in the inlay substrate for accepting theantenna structure; and after forming the trench, disposing the antennastructure in the trench.
 2. The method of claim 1, wherein: the trenchis several times wider than a cross-dimension of a single turn of theantenna structure.
 3. The method of claim 1, wherein: the trench isapproximately as deep as the cross-dimension of a single turn of theantenna structure.
 4. The method of claim 1, wherein: the antennastructure comprises a wire, a foil or a ribbon.
 5. The method of claim1, wherein: turns of the antenna structure are laid into the trenchsequentially, turn-by-turn.
 6. The method of claim 1, wherein; the turnsof the antenna structure are scribed into the trench using a sonotrodetool.
 7. The method of claim 1, wherein: the antenna structure ispreformed, and disposed as a single unit into the trench.
 8. The methodof claim 1, further comprising: connecting end portions of the antennastructure with terminals of the chip.
 9. The method of claim 1, furthercomprising: dispensing glue in the trench.
 10. The method of claim 1,further comprising: disposing a layer of adhesive over the inlaysubstrate.
 11. A method of making a transponder comprising: providing aninlay substrate; forming a recess in the inlay substrate and installingan RFID chip in the recess; forming an antenna on a carrier film;separating the antenna from the carrier film; installing the antenna onthe inlay substrate; and connecting termination ends of the antenna toterminal areas of the RFID chip.
 12. A method of forming a transpondersite comprising an inlay substrate, an RFID chip and an antennastructure connected to the RFID chip comprising: preparing a pluralityof transponder sites on an inlay substrate, each transponder sitecomprising a defined area of the inlay substrate; forming a plurality ofantenna structures on an antenna substrate which is separate from theinlay substrate; and removing given antenna structures from the antennasubstrate and transferring them to selected ones of the transpondersites.
 13. The method of claim 12, wherein preparing a plurality oftransponder sites comprises: installing RFID chips in recesses at thetransponder sites.
 14. The method of claim 12, wherein: a plurality ofantenna structures are transferred one-by-one from the antenna substrateto selected ones of the transponder sites.
 15. The method of claim 12,wherein: a plurality of antenna structures are transferred all at oncefrom the antenna substrate to selected ones of the transponder sites.16. The method of claim 12, wherein transferring comprises a contacttransfer process.
 17. The method of claim 1, wherein: the antennasubstrate is formed of a material which is different from the materialof the inlay substrate.
 18. The method of claim 12, wherein: the antennasubstrate is formed of a different material than the inlay substrate.19. The method of claim 12, wherein: the antenna substrate is in theform of a web, and the antenna structures are formed in a single row onthe web.
 20. The method of claim 12, further comprising: forming a widetrench in the inlay substrate for accepting the antenna structure; andinstalling the antenna structure in the wide trench.